UberEats - takes more than authorized amount

They took more money from my account than they were authorised to take, so I went to the bank to take back my funds. Now they are refusing to apply their promotion that made me buy from them in the first place. Its been 8months!!!! No one at their support centre seems to understand their mistake and they refuse to give me a manager's number to try and explain it to a higher level of employee. I have tried everything, can someone please help? What do I do?