Paytm Mobile Solutions — Change the old registered mobile number

Address:

Sonbhadra, Uttar Pradesh

I lost my sim and mobile both (someone stole my phone ). Now I bought a new phone and its need otp of old number.
Some handful of money left in my account. So I want to reuse my old paytm account. Plz help me how I change my mobile number, that I can use my old account.
I already emailed to paytmcare but they didn't respond. I am in trouble. Plz help me