Flipkart — Account related/ trouble adding phone number

Address:

kerala

I am unable to access Flipkart pay later service since I am unable to add my phone number to my account. it shows that the user is already registered when I try to add the number. I had an old account on same platform which I am no more using because the mail id was compromised. I have deactivated the same and started this new account. How can I add my phone number to this new account, so that I can avail all the services.