Submitted Blackberry under warranty in June 2015

My name is Gordon Horn. I have a contract with Telkom Mobile. ***) My Blackberry 9720 started to re-boot up to 5 times a day when a receive calls. I submitted my phone on 06/06/2015 for repairs. I submitted my phone to Telkom Polokwane in the Mall of the North. Outlet details Shop L51 Mall of the North ***. My warranty expiry date is 23/06/2015. My phone was send to 1 Johann Birkart Street Spartan. I received a sms that I must pay R900 fot the repairs. I went to the outlet and they send a email to indicate that my phone is under warranty but that I requested that my phone must be returned. Since then myself and Polokwane outlet were unable to get any response from Telkom. 12 emails have been send by the outlet and 2 by the outlet manager without any response. I've been 15 times at the outlet and on Thursday 10 December 2015 the outlet personnel indicated that they really don,t know what to do. I informed them that Im going to report the matter, and they said thats all I can do. for 7 months now I dont have a phone but im paying my contract monthly. can you please assist me as Telkom Mobile is unable to get my phone back or even any response from them.