My husband has the above sim card in his phone

My husband has the above sim card in his phone. I whatsapped him this morning and I re eived a response in Xhosa. I have sent more messages and keep getting a response from another person. The SIM card shows no service. I phoned MTN ***** tonight at approx 17.55. I was told that the phone was deactivated by MTN because we didn't buy airtime to phone out. But was reactivated on the 5th April and the number was given to someone else. But he has been using this number up until today and. this person has access to all my husband's contacts and has been making calls to them and his profile picture still shows on all messages and phone calls made to his contact ***