How Can I reach out support center?

I got unintened charge fee for corpus
during last april and may.
With regard, I want to contact with support center for handling such problem
But I could not login in to vectara support center.

How can I make contact with them? page shows that
it is only available to registered users.

But I cannot find way to register.
I already have account for vectara platform

Please drop a private message to me with your email address, account id, and why you think it was unintended, and I can follow up over email.

How can I give you a private message? Im kind of new to this kind of forum.
So I don’t know how to deliver you my email address, account id etc

It seems you are already in touch with our finance team. Your account id ends in 962, correct?

yes, I do.
I’ll just keep in touch with finance team
My account id ends with 962

BTW, this post was before I made contact with finance team