Bad service from mtn longbeach mall

Last year September I took out a phone contract with mtn longbeach.I took the phone in, the first week in December, because it was heating up.the sales lady, said I should come back in 21 days, I went in a bit later, because we went on holiday.when I came to the store the phone was still at the store, it wasn't sent to their tecniitions. Then it eventually went to the tecniitions, they send it back after another two month, the sales lady said it came back, the tecnitions didnt even looked at the phone they send it back , exactly the way they it was send, then after another few months they send an email to the sale's lady, saying the phone is water damage and it will cost me R650.the phone came back, mishandled, full of scratches and the box was broken, the phone was still new when I handed it in.and it was still not fixed.lockdown happened and I went back to see if my phone is fixed. Another month and a half, the sales lady said, the charge is R1000 and not R650 anymore. I had my phone in my possession for two months, and mtn had it most of the time.I do pay faithfully every month.as a loyal customer, i feel angry, disappointed and frustrated.