Repair centre breaks phones more often than fixes them!

In mid August 2018 I took out a contract with Cell C. In November 2018 the device' battery was dying faster than it should so I sent the device in for repairs. The phone had a tempered glass screen guard from day 1 & was in excellent condition. When I picked the device from the store ( after I had to contact the store regarding the phone on the 9th of January 2019) I saw that the screen had a scratch. The store refused to help me and when I escalated the complaint at Cell C they insisted I book the phone in again. When I received the phone (yet again I had to call the store querying about my device) the phone was dead. After charging the phone I noticed that the power button doesn't work any longer. I yet again contacted Cell C & their solution is for me to book the phone in again. After me refusing, the consultant kindly forgot about my complaint. This is an ongoing issue with Cell C. Which ever store I have taken out contracts with I have had issues with them. They took a perfectly good phone, broke it and now I left paying for a contract I hardly got to use. The store I am currently having this issue with is Pinecrest Cell C. The manager and staff are the most unhelpful & clueless bunch I have ever come across and the repairs centre seems to be even worse than them! I will not use Cell C in future & advise everyone I know as well not to use them. Constant disappointment & pathetic customer service!!!!