Sub standard phones supp**** by Cell C

I recently opted for a Microsoft 950 for my Cell C contract renewal. After 3 weeks the phone started endless troubles by constantly overheating and a shortened battery life of 3 hours. The phone was taken back to Cell C and after 6 days was returned to me - supposedly repaired by a software upgrade. The phone worked fine for only a week where after exactly the same problem symptoms re-appeared. On returning the phone back to Cell C I was told that the phone would need to be booked in up to 3 times to be declared faulty for replacement. I find this unacceptable - every time I have to run back and forth to Cell C and wait over a week for my phone to be looked at. After spending many thousands of Rands monthly this is the service that the company provides?