If you do it the wrong way you can't ever not have done it the wrong way.
You can fix it - "fix" it - at least some of the times. You pay back the underestimated sum, you correct the misspoken words, you calculate a new rate based on the proper inputs. That's better than nothing. But you'll still have done it the wrong way. It is literally easier to get somebody out of Hell when they've already gone there than to un-make a mistake, in the sense that literally speaking you can do the second thing, kind of, in everybody's subjective timeline except your own and probably the gods', with a ninth circle spell, whereas you usually don't have to get all the way up to ninth just to un-Hell somebody. And unlike whether or not Jaume goes to Hell, which is up to the gods doing complicated god things that are all full of things being done in wrong ways, whether or not Jaume does things the right way is fully up to him!
Even an enchantment will run aground if you're really serious about it, or at least that's his understanding. A suggestion can make you do something that wouldn't normally be too out of the question for you. A suggestion could probably make him beat his best slave all the way to death even though that'd be a waste, or give away his theater tickets to somebody else because it was made to seem like a good way to curry favor even though it wouldn't be. But Jaume is really serious about doing things (the important things) the right way. A suggestion will not make Jaume Agramunt tell a lie any more than it will make him slit his own throat, because the only thing worse than being in Hell would be having been wrong, forever, and ever, and ever, irrevocably.
(It's not that he thinks being in Hell is going to be great or anything but there doesn't seem to be a whole lot you can do about that. Most of the other fellows at the bank, foreigners looking for quick gold in the desolate finance sector of Cheliax, wind up Evil even if they didn't start that way - somebody makes a joke about it being in the water - and Jaume has no way to leave and drink different water, so: the thing he can do, with respect to his eternal fate, is to simply not ever do things the wrong way.)
Jaume is not a popular man. He is sufficiently offputting that his money hasn't landed him a wife and even the other Abadarans don't really enjoy him socially. He doesn't know how to play the game, any games actually, he was once introduced to the concept of poker and flung his hand of cards in his brother-in-law's face, but most importantly the game of Chelish status jockeying. Is he supposed to be bribing someone? Doing favors for people? Exhibiting the exact right mix of Asmodeanism and patriotism and self-interest and cruelty and so on? Well, he isn't. He is busy doing everything right all the time.
There are certainly occasions where this leaves him vulnerable to various sideswipes from other people. Sometimes doing things right is a meaningful protection there: once some fraudster decided to claim that Fidcuia Agramunt had pocketed the difference between his assessed value of her mortgage and her opinion of the actual value, and the cleric she complained to nearly pissed himself laughing, before going to responsibly check with an Abadar's Truth (because that, too, is doing things right). Sometimes it's not. There are probably interesting stories to be told about why Jaume lives in a shabbier flat than you'd guess from his payscale, why his letter of excused absence from a public execution got lost in the filing system, why the woman who came closest to deciding to marry him suddenly had urgent business that prevented her from making any further appointments to see him. Jaume does not really think those stories are interesting, though, apart from the punchline, and the punchline is not what happened to him. They already have their comeuppance, whoever was going around playing at such nonsense: they will have been wrong, forever, and ever, and ever, and ever, no matter if the last moon and the sun die by murder-suicide and their souls are annihilated in an interplanar war and the mechanism of Creation itself winds down leaving only wisps of chaos behind - they will still have been wrong.
Anyway, Jaume is drafting a letter to the reinsurance department at the church of Abadar in Absalom, which ought to owe them a fair sum for the excessively correlated risks that have befallen various insured parties in certain strategically relevant parts of Cheliax. They have misunderstood article six of the contract (it's plausibly different in Osirian, but that is not the version that they signed) and hopefully with that cleared up everything will be sorted. Then in comes Bittore, one of the foreign Abadarans who extended his stay in Cheliax when there was a regime change, holding a bulletin with one hand and a laugh behind his lips with the other. "Jaume?" he says. "Jaume, the new government's drafting a constitution and they want church representatives, and they want them native born."
"Well, how much do they want it?" Jaume asks, dipping his pen and double-checking a bit of division scratchwork his argument hinges on.
There is, it transpires, a reasonable stipend. He packs his things and his person and he makes his way to the constitutional convention.