Only company that repairs Fondi won't fix device

My son got a Fondi for Christmas. It slipped off the couch and the screen smashed. The only company that repairs Fondi is Sahara. I took it in on 19/01/2015. They said they were getting new prices the next day, then it would take 40 mins to replace and they'd call me to collect the device. It is now 01/03/2015 and I have still not received a call. I have phoned twice only to be told they are waiting for stock to arrive. They said they would find out what was happening and call me back. I have still not heard from them. They won't replace the screen or the device which renders the Fondi tablet as useless as them. We spent a lot of money on the device as a Christmas present for our son and he has not been able to use it.