I'd prefer to do what I am legally required to do, which appears to be nothing.
That doesn't seem to be particularly hard or costly. I can only imagine all the troubles that would occur if I told them about what appears to be a mistake. Next thing you know they put a hold on the savings account and draw the money out of my checking account, followed by another department noticing the mistake and withdrawing the money yet again potentially resulting in overdrafts, bounced checks, etc. Nope, I think I'll let the bank take whatever time they need to correct their mistake and not muck things up by sticking my nose in their business.
After all, zinger swears up and down that they *will* correct their mistake. I'll give them their full three years to do so.
Had a friend dealing with the same bank and the mistake went the other direction, he's spent months trying to straighten that out. Nope, I don't need that kind of time consuming hassle.