giving my number to another person

I'm so ****ed off with the service rather lack of, received today from #telkommobile and partner #selldirect. How do you do a sim swap on my active number and give it to someone else, what ****** business is that? Selldirect called and upgraded my line and delivered they phone a month later, and I was told my old sim will be swapped and I will use the nano sim received with the phone. today 18Jan2016, my old sim didn't have service, so is the new sim card. Now I'm out of the loop my clients can't reach me. Called selldirect for more than 3 hours no one is picking up. When I call my number, that is suppose not to have a service, that number rings ( ***) and someone picks up. The person on the other line received a new phone and sim from #telkommobile and his surprised to be receiving my calls. This is not professional at all. .. I receive confidential information on my number and now my is with someone out there. this is *******.