Phone in Repairs for 3 Months

I am Actually Fed up with MTNs Repair Centre and I don't know whether to blame Sony Or MTN. On the 13th of December 2014 I sent my phone in for repairs because it had a problem with the vibration which was noisy and cranky. After sending it for repairs a week later I did a follow up and I was told they waiting for spare parts. Hence when I did another follow up on the 12th of January 2015 I was told that they sent me an SMS which needed my approval of a R1784 quote, and I did not receive that SMS, I then asked them to Send it to my MTN Number. When I asked why I'm being charged such a high amount I was told my SIM pins are broken due to physical damage and till today I don't understand how that happened because that was the least of my worries I have never had a problem with my SIM Pins. After replying to the sms twice I did another follow up 2 weeks later only to be told that they did not receive a response and they declined the quote. the call centre agent told me they will send a request to the repair centre notifying them of the quote approval, after this was done a week down I received a quotation sms of R1971 which I don't understand why I'm being re quoted again