Very Very Bas Service

I did my upgrade with Vodacom on the 9th of March and I got my phone on the 13th of March. I was not happy with the phone. I then called Vodacom on the 18th of March the phone was only collected on the 28th of March. I was told that I should wait for them to receive the phone before I can do another upgrade. I called them on the 3rd of April the person I spoke to said I'm must phone again on Thursday which is today they still don't have my phone. I am so frustrating because I don't have a phone. please help. I called RAMS the company that collected the phone from me, they tell me that the phone was delivered to Vodacom on the 29th of March @ 8'oclock in the morning. Since then Vodacom has done nothing. I'm always the one phoning them they promise to call back but they never do.