On two separate occasions a company has charged me for something and after I've made multiple calls and escalations (which of course can only happen during certain hours) they finally refunded me by saying "we'll make a one-time exception as a favor to you" even though they were literally stealing from me. In one case they only finally did it after I contacted the attorney general.
Honestly I don't even really care if it was a mistake (which are usually systemic issues) vs intentional, it is theft. In one example Comcast charged me a late fee even though I had autopay set up and they just missed running the charge. I wonder how many people just didn't notice.
I've long thought the only solution to these issues is to levy fines (or jail time if intentional theft) large enough to discourage the behavior. If it is still happening, keep raising the fines until it stops.