Paytm Postpaid — Refund

Address:	4/149 Eswaran Koil Street Okkiyam Thuraipakkam, Nehru Nagar, Oggiyamduraipakkam, Tamil Nadu, India
Website:	Paytm App

Am using the Paytm app. Recently I have activated my Paytm postpaid account they gave a 12k credit limit. By mistake, I have placed the request for 5k for google play instead of google pay. Suddenly I noticed and realized my mistake in the meanwhile I have received the voucher code of 5k but still, I didn't use that. I have contacted several times to customer service to cancel the code and refund the amount to Paytm postpaid account. But there is no proper reply. Kindly help me.