Rbl Credit Card - Not giving services

I took a new Sim card from Airtel in the month of Apr ****. From that day they have been calling me for payment of credit card bill rbl. I do not own any credit card and looks like the phone number received is a recycled number. The earlier person took the credit card and stopped paying bills. We tried explaining to every caller and they said that our number will be removed from call list. It didn't happen, then we escalated the issue to RBL credit card grievance email Id. They promised to remove the phone number but that also didn’t happen. From that day, they blocked our emails also and now they stopped responding to emails for our phone number. I have email proof for all the emails I sent to them. It is almost ** months and we get at least *-* calls every day. The phone is for my wife and due to all these wrong calls, she stopped taking calls from unknown numbers, not able to bear the recovery call harassment. Even without listening to the issue, they use bad language demanding credit card bill payment. Since she stopped picking calls, she couldn’t take up job interview calls also. This resulted in depression for her, she is currently in medication. Need your help to fix this issue once and for all.