Airtel — Cheating my hard earned money

I have paid ₹3536.92 for Airtel broadband monthly payment (fixedline ID[protected]_tn) on October 2021. The team told that we did not receive the amount & asked us to pay again. Moreover, they told us that the previous amount will be refunded in 7 working days. Believing that I also paid the same amount again. But it’s been almost 10 months, I still did not receive refund. I have all the proofs from the bank that I have paid the amount twice. I need my money back. Please do refund.