HDFC Bank — credit card payment issue

I had purchased a smart phone online using credit hdfc card. But the order was cancelled & money was refunded. But i have got the phone payment also in my credit card statement & last date to credit card payment is 16 jul 2020. I have tried contacting customer care through phone many times but after a lengthy process of dialing digits still not able to connect to customer care as, in the end they use corona pandemic excuse to avoid call & say they have limited employs & cannot take a call.