Bad experience with OP Bank - recommendation: AVOID

I've seen some requests for which bank to use and thought I'd share my recent experience with OP as a warning to others. I'll also be moving my accounts to another bank (as small as my accounts might be, it's my only option as a consumer).

Here's the story:

I pulled some money out of my account for change - various sized bills and coins. Let's say it was 625 euros. We counted the money on the counter and I walked out of the bank with two receipts and the money and went about my business. The transaction was done in two parts, the receipt doesn't line item the types of bills or coins you take, just gives a total amount. I didn't count the money again at home since we counted it together at the bank, as you always do.

Just under a week later I return to the bank to deposit the same amount of money (not the same exact money as it was mixed with other cash and coins). It was the same teller. I put the money on the counter, various bills and coins, and explained that I'd like to deposit the same amount of money I took out.

She pulled the money to her side of the counter and informed me that she just remembered that I had accidentally taken more money that I should have the week prior and that she would deposit (for example) 600 euros, but that she would check on 25 euros to see if I had taken more than we counted on the table together. Obviously this was a surprise to me, I had two receipts that added up to 625 euros and at the very least didn't notice that I had more than that when I left. I never received a phone call (I know they have my number because they call me to try and sell me more insurance more often than I'd like) or a message to my account saying there had been a mistake. Radio silence about somebody walking away with more money than they requested? Unless they were okay with giving away money, this to me is the craziest part of this whole thing.

So I asked her if she had a written note from when it happened. She said she did, but couldn't find it - which really just means "no" at the end of the day. I agreed that she could call me when she'd resolved the issue (this was my mistake - I should have had her deposit it and then we could hash it out after they provided proof). She called a few hours later saying she checked the machine that they take money out of and she had taken out more than we had counted together the week prior so it was clear I had walked out with additional money. They will be keeping the money.

Is that the only conclusion that can be made here? Couldn't she have just pocketed that money? I'm not saying she did, I'm simply offering that as an alternative possibility. All we have for proof is their machine receipt, my receipts that shows how much I took out of my account and her word, a week later, that I walked out of the bank with additional money.

I've had discussions with customer service as well as the local bank branch and they have only offered me condolences and no resolution (whether that is returned money or a solution to fix what is obviously a huge gap in process for a bank - I don't really care).

I know this is only one event, but to me this is enough to leave a bank. I used 625 euros as an example, but what if that amount was magnified? Would you be okay with this happening? Does the proof they provided relieve me of having to simply trust that they are right? As a customer am I responsible for their errors? Even if I had walked away with additional money, why would they not have contacted me so I'm not surprised (in a bad way) upon the next visit? What would they have done if I hadn't ever come back (I had never used that branch prior to this)? I've never had an experience like that from any bank in my over two decades of having accounts at various banks in various countries.

Recommendation: AVOID