I have had this problem for years. I keep telling them there is money in my account that is not mine... I'm talking a couple thousand dollars. It usually happens once a year, but this year it has happened again. I don't know if it is considered mine because it has been there for a couple months or if I should tell them once again. When I do tell them they act so shocked and don't understand where it is coming from and they just take it out of my account.

I would talk to the bank manager about your problem so that he or she can investigate the problem and resolve it.

If this does not work and the bank is a US bank you can file a complaint with the Office of the Controller of the Currency. Their website is: OCC.gov Home Page

No it is not your money, and they have the right to take it back and pull it out of the account. Have you tried changing the bank account number, perhaps someone with a similar number is making a deposit and it going into your account by error