Paytm — Regarding My KYC and pending postpaid amount

I have a PAYTM account linked with mobile no. - [protected]. When I completed the online KYC with PAYTM, I was able to use the PAYTM Postpaid services. I started using this service and My Cibil Score reached to 813.
Now, I changed my Mobile and when I Login into my PAYTM Account with my Mobile Number. It shows that I have not completed KYC. When I asked to PAYTM KYC Agent, He said PAYTM cancelled all the Online KYC's and new KYC are closed by PAYTM.
But there is an amount appx. 800 that I need to pay to the Postpaid Service and because my online KYC is cancelled by PAYTM. So, I am not able to PAY that (appx 800) amount. I want to pay that amount, otherwise, there will be interest on this amount and it will affect my Cibil score also. Please help me to provide a way to pay that amount.
Please !!!