CELLPHONE NOT WORKING AFTER I TOOK IT IN

A few months ago I took my Samsung Note II in to the shop as it was downloading something although my updates were turned off. The lady there worked on it and I also asked her to create a shortcut for my contacts. She lost my contact but told me she will put them back again. At home I realise not all my contacts were there. I went back the next day and Marthinus and another lady worked on my phone. They told me my phone must be factory reset. When I got home, my phone was not working at all. I went back again and were told to take my phone to Vodacom, which quoted me R2800 to fix it. I took my phone to Cell C in Heiderand and were promised the guy who works on the phones will try and fix it, but he is on holiday. Few weeks later I phone, just to find out they forgot my phone in the drawer. Few weeks later I was told my phone were sent to Johannesburg for repair. Got it back last week and were told they could not fix it because it will cost more than R3000. The phone was in perfect working order when I took it in to Cell C in the first place. Nobody ever phoned me back, and I feel Cell C is responsible for my loss. A R10 000 phone that was 2-3 years old. What must I do? Please help.