Cancel iCloud storage subscription

I had subscribed for iCloud storage from Australia, where I normally live.

I was visiting India and got stuck for more than 13 months!!! due to travel restrictions both by India and Australia.

In India I had to get a new Apple ID and a new password.

Old ID and Gmail address blocked by Google.

Apple keep charging me for the iCloud storage that I had subscribed in Australia because it was a direct debit arrangement from my Credit card. I cannot access my old Gmail address because it is blocked by Google

All I want to do is stop the direct debit arrangement for the old Apple ID and start a new direct debit arrangement for the new Apple ID and the new Gmail address from the original Australian Credit card. How do I go about it.

Can you please help me.

At 76years of age I am not that computer literate and I have to request you to be kind enough to guide me in a step by step manner in your reply.

Thanks a lot.

Ramesh Telang.