Vodacom think their customer time is worth nothing

I tried to change my daughters cellphone from a contract to prepaid account with the following steps 1. I went to your shop in Brooklyn on 18/3/2016 – But their system where off line. 2. I phoned *** on 29/3/2016 hold on for 15 minutes, without somebody answering my call. 3. I phoned *** again on 30/3/2016 hold on for another 15 minutes, without somebody answering my call. 4. I went to your Hatfield Shop on 31/3/2016, but I was Informed that it can only be done via the number I phoned, the previous 2 days. 5. I phoned *** number again. I hold on 22 minutes before my call was answered. I was able to change my number, *** to prepaid, but just after I gave the second number of ***, the line was drop. 6. I send an e-mail, but apparently , this was not possible 7. I then send 2 e-mail. the first did not go through – it gave me possible remedies But Vodacom decide just to cancel the number and not change it to Prepaid. After this I contact them via e-mail and phone (customer care) on a number of occasions as indicated below. 1/4/2016 Send e-mail trying to sort it out 2/4/2016 Went to hatfield to change contract to prepaid 2/4/2016 Went to Menlynn to sort it out 2/4/2016 Send e-mail trying to sort it out 5/4/2016 Send e-mail trying to sort it out 6/4/2016 Send e-mail trying to sort it out 8/4/2016 Send e-mail trying to sort it out 12/4/2016 Send e-mail trying to sort it out 13/4/2016 Send e-mail trying to sort it out 15/4/2016 Went to Brooklyn trying to sort it out 15/4/2016 Send e-mail trying to sort it out 16/4/2016 Send e-mail trying to sort it out 19/4/2016 Send e-mail trying to sort it out 19/4/2016 Send e-mail trying to sort it out 20/4/2016 Send e-mail trying to sort it out 21/4/2016 Send e-mail trying to sort it out 22/2/2016 Went to Brooklyn to change contract to prepaid 25/4/2016 Phone Vodacom Customer care x 2 26/4/2016 Phone Vodacom Customer care - Jared 28/04/2016 Phone Vodacom Customer Care- Sammy, Andre . All still I have no success. The query ref is S3-GSP27-7EMWB. It was even close on the 18/4/2016 without sorting it out. What can I do next?