BAD SERVICE FROM MTN

I'm so disappointed with the service that I'm getting from MTN my phone was ****** about 4-6 weeks ago and I've been using this number for more than 10 years. i called MTN to do a sim swap last week since i noticed that there was someone who was using my sim card as they removed me from the whatsapp groups and they needed the question and answer that i set up as a sim watch and by that time i couldn't remember so the guy didn't assist. On the second attempt i called and the lady assisted ask a lot of questions of which i answered and she said to me the sim card will be activated within 12 hours and i shouldn't take out the sim from from the phone. the next day the sim card was still not active and when i called they told me that there was no query logged on Friday 2021/11/12. i spoke to the other lady who refused to give me the supervisor's details promising me that the supervisor will call me back and up to now I'm still waiting for the call. Today i went though my old diary found my question and answer only to be told that the system doesn't allow to perform a sim swap on my account. this is the worse service I've ever received and most of my things are linked to that number. i nee someone senior to contact me regarding this matter as any loss that will be incurred using that cell number will have to be resolved by MTN.