You have no grounds to sue upwork. In fact, they have grounds to ban you based on their TOS that you agreed to.
> Ceed Civil asked that I pay them off of Upwork to avoid Upwork's fees. I stupidly went along with it because I wanted things to go well with him
This here is the issue. It'd have helped if you actually read and understood their TOS, then you'll realize they have no reason to ban the freelancer as you transacted outside their platform
https://www.upwork.com/legal#terms-of-use
Upwork's TOS clearly states the following (see section 3.5, line starting with "You can’t go around us"
> 3.5 Other uses that aren’t allowed
> Upwork relies on technology and trust – here’s how we maintain those things. You can’t copy, share or give away your account. You can’t have multiple accounts and you can’t sell, trade or give your account to anyone else without our permission.
> You can’t go around us. In particular, you can’t talk to another user or ask for or share a way to get in touch - a means of direct contact - outside of Upwork before you’ve agreed to a service contract. This means you can’t add your contact details to a job post, your profile, communications or other content. (There are exceptions to this for Enterprise clients.)