Phone in for repairs and got it back broken

I On 4 January 2015 I gave my Blackberry in at Vodacom for repairs. Fault: It dies and must be rebooted. Battery last short whiles. Received phone back on 5 January 2015. I experienced the same problem as before just worse with the charging of the phone and took it back to Vodacom Lakeside Mall to repair on 6 February 2015. I was then informed that it can't be fixed and that I have to pay R800 to get a new phone. As this is a contract phone I'm suppose to have a warranty on this phone. I phone 111 and spoke to Harold who said I must go to the Vodacom shop and phone him from there. They phoned and nobody knew who Harold was. I'm not prepared to pay for a new phone as it is still under contract. Is this just a way to put sales on their books? This is bad service.