Cell C - Failure to port

My current contract with cell C ended on 17/7 and I am currently on pre-paid. On 20/7/15 I entered into a new contract with MTN and my number ***) had to be ported to new phone. <br> <br> Porting failed and MTN blame failed porting on Cell C. (Failure to release number).<br> <br> I have been without use of new phone since purchase of contract (21 days now).<br> <br> On 7/8 I received a phone call from somebody that entered into a new cell phone contract too who had similar problem and it turned out that my number ***) was allocated to him.<br> <br> Could you please investigate and rectify in order for my number to be ported to my new phone - A similar complaint was lodged to MTN - their req number is ***.