Frustrated and disappointed

I've been a customer at Mtn for over a decade and in the past years I never had problems with the network. I even recommended it to my family but this time around I ma really disappointed. So on the 4th of October they decided to block my number of which most if not all of my personal/banking accounts, social media accounts e.t.c. are registered to, their reason being that I haven't topped up my airtime for more than 3 months. So I needed to buy airtime to show that the number is active,. What bugs me is that can't they see that it's active since I get calls on that number, or through me using my momo. I mean I am currently unemployed and buying airtime is not a priority in my life, and for me it's a bit unnecessary as I have access to wifi at home so I normally just use whatsapp. But cutting the long story short, after my sim was blocked or cancelled I kept trying to contact Mtn using the 135 number but I couldn't get any assistance for over a month or so, I even tried using Mtn chat on whatsapp as well but still I got no help.

I then tried again in the beginning of November using MTN Chat and I was informed that MTN gave my number to another user on the 9th of October, literally 5 days after they de-activated my sim. like if they know that their contact service is not quick at handling queries or complaints why do they rush to give away my number. It really is stressful because I know people who haven't even bought airtime for more than 6 months yet they still have their numbers.

And what frustrates me the most is that my whatsapp was now blocked as Spam, i suspect it's the individual who got my sim or one of their contacts and on top of that the new sim that I got (the number) used to belong to someone and I cannot register the number on whatsapp because the previous owner is still using it.

I'm really not happy with all this as I had just recently got an opportunity to get employment and now I can't communicate further with the individual that was going to plug me. I don't know what to do.