MTN gives my cell phone number to a company.

I am disgusted with MTN after my pay as you go cell phone number which I have been using for more then 10 years and on which I have been spending thousands of rands in airtime, sms bundles and data were given to a company on contract and I lost my number on 19 August 2015. What makes it even worse is that I am self employed and works in the entertainment industry and I rely heavily on my phone number for business. I have been to MTN in the Cape Gate shopping centre more then 5 times and it is more then 2 weeks now and the issue has not been resolved although numerous phone calls have been made to Johannesburg. I am loosing business every day because people can't get hold of me and it is becoming that time of the year where clients contact me for entertainment for their end of year parties and festivals,this is very frustrating and totally unacceptable!!!