Still not done after calling twice

I have called twice to have my number ported to pre-paid. Once in December with reference number *** and nothing was done. I called again on 6th January with reference no: *** and it has still not been done. It is not that hard to do and can't possible take so long. Please can you escalate. It is exactly this terrible service from MTN for my reason to not renew my contract and move to pre-paid. <br>