blackberry phone deleted my info

I'm having a blackberry z3 which is on contract today morning when I woke up it was asking me for password which I did put and it kept on revoking it, until it deleted my whole info. Last nite I started to get the massage that say I must enjoy my watts up for life and then today it does this, I called cell c technical what I was advised was to update the software which I did try to do in a cell c store but it kept on stopping when it is on 89%. So today it deleted all my info just like that why would they sell a phone were else they don't have solution when it comes to this problem I'm having. Poor poor poor service.