Empty promises and bad service ever

I applies for a new contract and it was approved. I gave them all my details. I got the phone and the phone (microsoft lumia 535) gave problem same day, it didnt want to log and charge. I reported the fetched the phone in time. I called in just to check what was the problem with the phone, they told me my obf was approved and they will replace it in 7 days. I waited for more than 7days and i get nothing from cell c, no call, sms, email etc. Just to tell me whats going on. Then i called them after 3 weeks, they said their out of stock, maybe in a week they will get the stock. After a week i called, they started to give me confusing reasons. I am still waiting and its been over a month waiting for my phone to be replaced. I am not happy at all. They must just replace my phone.