Bad service.

I did an upgrade in May and the consultant who was assisting us said at the end of May they will debit the old installment and only end of June will our upgrade installment. End May the installment goes off and after a few days I get an sms that my name has been handed over to lawyers for a collection of R1558. My hubby went to the store and he was told the billing system is behind all will be sorted. After a few days again the sms started coming again that I have been handed over. I called their billing department and they couldn't find my profile. End of June the debit order went off and I am still getting sms that my account has been listed. I am getting no assistance from the store. My name is now listed yet the debit order goes off every month. Such bad service.