That Time I Got Reincarnated as a Slime: Tensei shitara Slime datta Ken

[David75]

It's true that the problem is a bit contrived in that each individual merchant would have requested the proceedings of the deal BEFORE coming to Jura. They also need funds to restock, to travel to Jura. So they probably would have asked for cash before coming or at least right before the festival so that both parties show their good faith: merchant there and with goods, Jura paying a percentage upfront.
Also, no complaints about their jobs, so they are professionals who did their jobs right during the festival.
A strange situation indeed.

[Kraco]

The more details you list there, the more incompetent it just makes everyone look like. The only explanation, that woud save anyone's face, would be for the mafia (eastern merchants) to have been there from the beginning. If their man had acted as the middleman, handling those affected merchants' case with Jura-Tempest, it would have allowed them to make both parties have totally different understanding on the negotiation results. If there were no negotiations in the first place and Jura-Tempest just issued an open invitation to all foreign merchants, to come if they want to come, then it would be 100% those merchants' own fault. In fact, agreeing to pay them only in dwarven coins is the very thing that made Jura-Tempest lose face. I don't know what kind of backwards logic dictates that using your own payment method would be less honourable than using a foreign one.