Worst service ever

My son's phone was ****** on 27 December 2018. The phone still has not been blacklisted, despite more than 10 requests via calls, e-mails and visits to MTN The Grove. I did a simswap , paid for that and now the new simcard is cut off. I get no replies from any body - not customer care, Karabo Mkhwebane or Sharon Hlongwane.