bad attitude/unfair treatment

I have contract phone with Cell C which was delivered to me on Monday, April 13, 2015. I cannot remember the name of the salesman that sold the phone to me but our agreement was that I will retain my old number \***". After receiving the phone I was shocked to notice that my old number was not linked. I phoned the call center they failed to assist me. I wrote them an email complaining about this their response was that they will give me a call on Monday"