Problem with a lender or other company charging your account: Checking or savings account

I don't know what happened all I know is that these people keep taking $30.00 out of my account over and over and over I've never authorized that I didn't ask for that I don't even know what it's for I've asked him to stop I asked him what it was for I even got a refund from my credit people however I am not going to keep putting up with this and I am not going to keep paying they've taken about $300.00 for me now in $29.00 increments over and over I don't even know what I'm supposed to be paying for