bad service

i am having a contract with mtn and last year in april they upgraded my contract by their sub-contract(Mondi) and I told them that when they deliver they must call me on Vodacom but they did not and they send the device back to Mondi and when I try to do some follow up, they are taking me from pillar to post and they are busy deducting money from my account. I am paying for the device that I don't have. I have calling them every day and I don't get any help.And now mtn are telling me to upgrade my contract which I don't want to upgrade I just need the device that I am paying for that's all