MTN SIM CARD NOT RECEIVING MESSAGES

My biggest regret. I have just switched from Vodacom to mtn with the hope of better improved services, little did i know that i was justing digging my own grave. I have ported my number from Vodacom to mtn 2 weeks ago, but ever since that I am unable yo receive or send any messages. I have called mtn customer care on so many occasions and no one have been able to assist me, i even went to Loch Logan Mtn shop in Bloemfontein, the gentleman who was assisting me said it will take 2-3 hours then I will be able to receive messages. But till now im still *****ed up by mtn. I even changed phones like 3 times, but still no messages coming through. I have missed out on so many important messages because of this. Now I can't even port out because I don't receive the otp or any sort of messages. All they do is to lie to me and I'm gatvol. They don't even bother to follow up.my numbers are ***