Unauthorized repairs to cell phone

Submitted apple iphone 5 on 23 Feb 2015 to check faults. No explanation given that apple only carries 12 warranty and not the 24 month vodacom warranty. Repair collection slip (***) clearly states quote before repair as well as if repairs are in excess of R0.00 a quote will be provided. I received a phone call from Game Richards Bay on 16 Mar 2015 to say that repairs are completed and the repair costs are in excess of R3000 and Vodacom will not release my phone until amount is paid. I have never received or accepted any quotation or phone call for the repairs to my phone, neither have i received a breakdown of the faults found. I would like to know who authorized the repairs and i want my phone returned to me ASAP. I will not pay the repair costs as i did not authorize this. I sent a complaint email to Game customer service (***) and have not had any feedback. Please assist me in this matter as this does constitute as *****. (Phone serial number ***)