Nokia Lumia not working under contract

I went to Cell C at Menlyn shopping centre to renew my contract. I was told by Kagiso that the best smart phone they had in stock is the Nokia Lumia. I renewed my contract. Since I recieved the phone I have had constant problems. I cant go into he intranet and whats app doesnt work. I have been to see Derrick at Mall at Reds Cell C branch numerous times. He has done his best to assist me but is unable to get it to work. Derrick informed me that Cell C has a problem with microsoft office and they cant get it right. I visited Microsoft in Menlyn twice and they also say that the operating system for these Nokia is microsoft and they cant get it to work. Both admitted to me that this is a problem that has been going on for some time and both cant fix it. I went back to Derrick this morning asking that they replace my phone as I need these two features for my job. He said I must lodge a complaint and in the meantime I must take out another contract to get a new phone. I was forced to do this as I need access to intranet, mail and Whatsapp for my job. I want my one contract cancelled!! Why must I pay 2 contracts when Cell C supplier cant get it 2 work. This is with all Nokia phones via C