How to add more than 10 persons to sign a document

I have several documents that I need more than 10 persons to review and sign. It is a big hassle that I either have to leave some people out or re-distribute the same document to the remaining people that needs to sign.

I have contacted customer support on the chat and phone. The chat supporter told me to upgrade my personal account to a business account. That is not possible on the website so I tried to call Adobe - I got thrown around to different locations in the world resulting in nothing.

Are there anybody who can tell me how to:

1. Add more than 10 people to sign a document.

or

2. Upgrade my account to a business account online (and confirm that this will result in the ability to add more than 10 persons to sign).

Thanks,

Jens, Denmark