Airtel Prepaid cannot be recharged online

Looking for someone who has faced this issue in the past

Ever since I ported into Airtel, I've not been able to recharge it online - both on their app/website, as well as Paytm and others... Every time I need to do a top-notch, I need to visit a retailer..

This has been really frustrating and the folks at airtel have done nothing even after multiple complaints over the last 2 months..

If anyone has faced this issue in the past - please let me know how you finally resolved it..