MTN running blatant ****s now?

So I have been spammed daily by phone calls. If you search the number on Truecaller it comes up as MTN. I decided to answer the phone this time but turns out it is some or other mobi connect phoning on BEHALF of MTN trying to upgrade my contract. They have all my details so clearly MTN is selling credentials to other companies for profit. Which without explicit permissions, is *******.

Care to explain MTN?