Poor service at MTN

I have recently discovered that MTN has issued my number which I have been using for more than 13 years to another customer. The funny thing about this whole issue is that I didn't even stop using this number. So I'm sitting with a number that is on contract with another MTN customer. To make matters even worse is that I have received any assistance from their consultants. All that I'm told is that this matter has been escalated. I could be at risk here as someone else might be using my number for some malicious reasons.