Strange subscription problem

I have a monthly subscription for a Zoom account that I will call Account A. Every month, my credit card is debited and I receive an invoice for Account A at a particular email address.

However, when I login to Zoom via that email address, I arrive at a different account – not Account A but Account B.

I want to cancel my subscription for Account A ... but I can't, because I can only access Account B.

I don't know if it's possible to have multiple accounts registered with the one email address. In case it is, I reset my password with Account B, hoping that when I logged in again via the email address it would take me to Account A rather than Account B. Unfortunately, though, it took me to Account B.

Does anyone know how to solve this problem?