Phone back and forth for repairs for 5 months

My father has a contract which renewed last year Aug with a new Nokia Asha handset.In June this year his handset started giving problems. It would spontaneously switch off. He'd restart, enter pin and it would switch off again. He took it the East London, Quigney Cell C branch and it was sent off for repairs and returned.This was done 3 times & each time the problem persisted. He then took the phone to Heminways branch where the phone was tested and found faulty and again sent off for repairs.By this stage, my father was fed up and requested a new phone to replace the handest which is still under warranty.He followed up on progress via phone and when he asked the branch phone him to give feedback he was told they were TOO BUSY TO PHONE HIM.He threatened to escalate the matter and finally had some response in the form of confirmed authorisation to replace the phone. They did not have stock of the same phone and offered some ruddy little phone of unrecognisable brand. During the 5 months he has been using a phone without smart functionality and paying for service he can't access. That it took 5 months and a threat to get response is absurd!Patience was paid with utter disregard.