You Can't Support What You Didn't Record

Support asks a year after the payment: "Why did the customer receive €117? And which card did we charge?"

A supportable system answers that with one query. If answering means trawling archived logs, guessing what the exchange rate was that day, and hoping nobody edited the payment method since, you don't have a supportable system.

Record the decision at the point you make it, and never destroy the data it points to.