MTN recycling numbers

MTN gave my number to someone else I have been using my cellphone number on MTN for most 12 years. I have ALWAYS PAID MY ACCOUNT ON TIME BY DEBIT ORDER. When my contract got cancelled in February, I requested to keep my number on prepaid. I went overseas with roaming activated. Which never worked and MTN doesn't respond to my emails. It was VERY INCONVENIENT TO ME while travelling abroad. Yesterday I got logged out of my WhatsApp and tried to get my WhatsApp verified again but MTN gave my number to someone else. They said that this person doesn't have any access toe previous messages or personal data but that person started messaging some of my contacts. He has been receiving all my messages,photos personal information such as ID and bank info in the meantime! MTN just says they can't do anything about it. CAN I SUE MTN FOR BREACH OF PRIVACY / INCONVENIENCE CAUSED?