Mtn bad customer service to network and sim card

Mtn has cancelled my Sim card due to that my phone was broken and but when it come back the network was working but now no network service and i have use that number more than 18 year and i cancelled my contract 2010 and i have apply many Jobs with that number i can't loose that number please wand when i call it it say its not on MTN service and no one is using it and i need it back and another customer service by the name of Zandile said it was cancelled on 11 November 2020 is it because i did put air time am heart broken and depressed i need my number back i hv rica that Sim card what was the use of Rica?