MTN Repair Service SHOCKING!

My phone went in for repairs in June (screen was cracked) I paid excess and it was repaired. Not even a month later the screen was cracked again. This time it was because of the screen was not put back correctly and the crack was under the glass panel. Excess doubled. I explained to them I will not pay excess because it was not my fault. Everything they ask me lot of questions and tell me they will get back to me. Every time they come back with same answer. I am NOT prepared to pay for something that is not my fault!? The service is SHOCKING! I am with MTN for more than 25years. Got 4 cellphone accounts with them, but NEVER got such bad service from them! I am NOT happy with the fact that i need to pay excess for something that is their fault!? Struggle for more than 3 months now to get some sort of answer and solution form their side…… Correspondance with Happy, Raquel September, Mamello, Zanele, KamoheloM, Nqobile, Fortune……