car installment not deducted for two months

Good day, my son Lesego Majebe bought a car in January from STD bank, gave them all his banking details including signing debit order agreement. This is the second month that the money has not being deducted and he tried contacting STD bank to find out what is the problem. Today I got a message from STD bank telling me that I should come and sort out the car payment as it is in arrears. I called them to find out which car are they talking about because I don't have any car finance with them, I checked with my sons id number to make sure he did not use my telephone details to apply for the car, , I was told no he used his details, when I explain I am being told HE MUST phone , despite the fact that the error is on their side, no one wants to listen. THIS IS BAD SERVICE.<br>