BAD SERVICES

I have made payment to my mothers account on 30\06 and it went through and today she gets a phone call and numerous messages to say that her account is overdue when payment was already done!.....I have emailed all the proof that payment was made and we also phoned through to the call center, and they said that we need to email all the documents to another contact to investigate and if we do not get any reply, then we need to take all documentation through to a Foshini branch or sister branch

This is utterly ridiculous at the level service we get from these retailers I am really not happy and its putting my mother under stress!!!!