Poor communication/paid and onlygot further damage

I handed my Samsung note in for an internet problem on 12/03/2015. MTN quoted me via sms R951.98. I queried that amount and MTN rep**** that the battery was faulty and out of warranty and had to be replaced. I was unaware of such problem. MTN also said on various occasion that the amount was R571.19. I then excepted the amount of R571.19 via telephone and email. MTN took their time in fixing my device and I had to drive the communication process myself. Eventually my device was \fixed"and suddenly I was billed R951.98 again. I emailed and phoned AND visited MTN Irene mall and I was promised that I supervisor will get back to me - which never hapened. I eventually paid the amount of R571.19. Got my tablet back today and it is completely *****ed-up. It won't even start up. In the mean while I am paying for an expensive internet contract which I don't get any value of. MTN's service is really ****ty. Email conversation and reference numbers available as proof if needed."""