Worst service ever

On 30 April 2015 I went to MTN in Wolmaransstad with a problem on my phone. The night of 29 April i received a mesage but my screen were dead when I looked closely there were a crack on the screen of +- 1 mm. The lady at Mtn advised me that she received phones in a much worse state and because the phone is under guarantee there will be no charge. I booked the phone and after about two weeks I received a sms that the cost for repair is R6620.00 (more that a new phone) I again went to the branch and said they said there will be no costs for the repair. The lady were rude and said there is nothing she can do I must pay the quotation fee of R330.00 and they will return my phone without repair. I made the payment and went to the branch week after week but she advised that they are on strike and cant assist. During August I started to visit three times a week to get reponse. I did not receive one phone call from them during thos time. In August I received the phone back in a worse state the screen were totaly damaged as well as the sides and back of the phone. I refused to take the phone. They phoned me and said they took action against the guilty party but refuse to replace or help me.