Bad credit rating due to staff's mistakes

I took out a cell phone contract mid october for 229 p.m for a samsung a21s at telkom woodburn square. I took all the relevant details etc bank statements with my correct banking details and obviously proof that my salary goes into that account. I wasnt worried that no payment was deducted end of october as the guy helping me said it would deduct end of november.

End of november came no deduction. End of december no deduction . Tried calling the accounts dep but no answer as it was over the holidays. Got a sms now saying my account is suspended. Was my details not captured correctly and Who's flippen fault is it that my details were captured incorrectly?! I have never been in arrears for any of my accounts and this will surely affect my credit record.

I want answers and NO i will not pay a large back payment, NO i will not take ownership for your staff's incompetence. A manager verified in my presence if all was ok and in my prescence she gave the thumbs up. I want to be contacted so that this will be sorted ASAP