Product: Checking or savings account

My M & T Bank checking account became overdrawn by small purchase that I made via XXXX and my XXXX balance was insufficient and it mistakenly used my M & T checking account as the default backup funding source. M & T covered the debt and then charged me a {$38.00} overdraft fee. I did not opt-in to the bank 's overdraft coverage plan so they should have just rejected that transaction and any subsequent transactions. Instead, they just paid or rejected 3 more small charges on that day and charged me {$38.00} for each occurrence totaling {$150.00} so my account balance was negative {$180.00}. The majority of that negative balance resulted from the bank 's fees. This was on XX/XX/XXXX. I called the bank when I realized this on Thursday, XX/XX/XXXX. I asked if they could waive these fees so I could deposit money into the account to bring it positive so it would stop any further bleeding. The customer service rep said she could not do anything but that maybe if I visited my local branch they might be able to assist me and possibly waive some of the fees. I also asked her to either stop or freeze the account or do whatever they could to reject any further incoming debits so I would not be charged additional overdraft fees. She said she could not but she did check my account and assured me no additional overdraft fees would be charged to my account. 
I was unable to make it to the branch the next day but was able to go the next business day on Monday, XX/XX/XXXX. I spoke with a branch representative and she was able to waive two of the fees but at this point, two more overdrafts had occurred, so my account balance was still too negative for me bring to positive. Again I asked if there was some way for them to freeze my account or reject any incoming debit transactions but again she said she could not.

I left the bank and the next day called the bank and asked to speak with a supervisor or manager. I asked for assistance with my account but once again they said there was nothing they could do. At this point, my account was charged an extended overdraft fee and now my balance is over - {$400.00} negative. And over {$350.00} of that negative balance is the bank 's overdraft fees. I asked to CLOSE my account and she said it can not be closed if it has a negative balance. I explained that I could not afford to fund it to get it positive and that it would just continue to be charged overdraft charges unless they could assist in waiving or even forbearing the charges for now for me to get the account positive. She said there was nothing she could do. I also attempted to use their on-line problem resolution ticket system but never got a response. 
This situation spiraled out of control due to the bank 's initial and mounting overdraft charges. If they had rejected those few small initial purchases it would not have dropped the balance so negative and I would have been able to deposit money into the account to cover any additional debit transactions. I did not opt-in to this overdraft coverage so they should have rejected those debits and they also should have been able to reject any further debits as I requested four times.

If M & T Bank had rejected the initial small transactions when the account balance was low it would not have been overdrawn and then I could have been able to resolve the problem by adding funds to my account. Instead, these fees just continued for every small debiit as I was unable to get my balance positive against the mounting overdraft charges. When I contacted them all four times they should have acted to resolve the problem.