So sorry about your lost sim. This happened to me about 2 weeks ago, and below is the message from MTN Customer Care when I contacted them. They will also send you a sim swap...
I have not used my number for a while because I am abroad. Now the number is not working. I can’t receive messages of make calls on my number l. How did I get my number back?
I was unable to to keep my Nigeria mtn number before leaving the country to Canada and I have not been able to use it here in Canada. So how can I start using it or keep it...
To Retrieve the PUK via USSD Self Service, dial *123*7*3# or dial *123# (MTN’s self-service USSD dial) and follow the prompt of inputting ‘7’-Self-Service, then ‘3’-Get your PUK...