Subscription Failure!

I have been using the Master Tier monthly subscription since past 1 year.

Recently on August 4th, 2020 I get a mail that D&D Beyond failed to validate payment and my subscription is cancelled.

Now when I try to re-subscribe it says error "Transaction not allowed".

I was using Paypal and my bank's debit card as the default payment option. Now even when I try to use my debit card directly it says the same error.

On raising a support ticket, they mentioned my bank has declined. I tried registering with my another bank account's debit card and the same issue!

Has any transaction rules changed? Is D&D Beyond accepting only credit cards now? -_-