Vodacom store in Clearwater Mall do not understand customer service

I took out a new contract at Vodacom in Clearwater Mall last Wed 13th Nov and charged it that night. At 10am the following morning it was at 7%! I also had some issues adding WhatsApp. I went back to the store the next day but was not helped. I then went back that Fri afternoon where they took the phone in to send it for an assessment, which was only done early this week. This is an out of bx failure and the phone should be replaced but I am still waiting. This is not acceptable as its over a week now. The store promised to keep me informed but I get nothing and have been back a few times but getting nowhere! They seem reluctant to quickly resolve my issue. Pathetic!