waiting 20 days for vodacom head office for answer

I gave my phone in for a speaker repair the 7th of April. Vodacom phoned me on the 9th and told me the I must bring my cellphone box, charger and headphone in because vodacom head office are going to issue me with a new phone because my phone are going to take to long to repair because of parts. My phone was send to head office and was received the 15th of April. I phoned several times to find out what ia going on and the respond from them each time is that thy are waiting for head office. I phoned head office on the 4th of May and spoke to a lady that told me as soon as a phone is received at their office it takes two to three days for them to respond. My phone is at head office now for 20 days and I am still waiting. Vodacom vanderbijlpark is of no help to try resolve my problem they are just sending emails to head office and I done think any body is doing follow up work. I am with out my phone now for nealy a month. Please help