WORST SERVICE EVER!!!!

I submitted my phone to MTN on the 12th of October at the MTN store Key West Krugersdorp. It was submitted to the repairs centre for a quotation. A quote was sent to me on the 15th of October for R2996.82. I then phoned to advise that my Insurance require an Invoice in order for them to pay for the damages. The invoice was only received a week later after I had to phone several times. I made payment of R2996,82 on the 30th of October. I was then told a couple of days later by the repair centre that the phone cannot be repaired and that they have ordered a new phone.I then heard nothing until today. Received another sms from MTN stating that I need to pay R1881.41 to have my phone repaired. When I phoned the repair centre I spoke to Tato Modise that sad she saw no other notes and can only see that I have to pay R1881.41 and that she will escalate the matter. When I asked to speak to the Supervisor she said she is on lunch her name is Sara Naidoo. I then asked to speak to the Manager, Rakesh Dajee and she said he is not available. When I asked for their e-mail addresses she said I can use the standard e-mail address and refused to give me their direct e-mail addresses.