Terrible service

My account was debited due to "early payments" but I did not receive an early payment so that resulted in a negative balance on my account. I advised cartrack to reverse the amount as they took the banks money, but I was asked to prove that they took the money and that o do not have any money. Now I have to pay the charges I'm incurring due to the negative balance. My issue is that there was no communication that they will debit at an earlier date now I have to pay extra because other people get paid early.