service center damages phone and wont return it

branch in harrismith as it was nor reading memory card any battery did not last when charged. Around the 28th of october i picked up my handset, it would not switch on, i assumed i had to charge it but the truth is the phone was dead. I went back to the shop and thabo gave disgusting service telling me that thats not his shop when i asked him to make queries, he just gave me a number. Minutes after i left the shop he calles to say i should pay R200 and something as my phone had water damage, i was shocked.i refused as they broke my phone. In december i called the service center, my request was that they return my phone in the condition its was in when they took it, tge three agents hung up my calls and refused to transfer me to management. Is mtn a company of *******? I need my phone back switching on like it did, your people broke my phone and are covering up. Imei *** , ***. Now i was told i oqw R470 and no explanation, sim blocked since 6 march and call center not operating