I'm unclear, from your last post, on where exactly your purchase stands.
Has the ownership/membership been transferred into your name? Does the resort have you in their system? If so, then it sounds like the selling and closing companies actually did their job. You could easily contact the resort directly, pay the MFs now and move forward. If you end up double-billed because you gave someone your credit card earlier, just ask the resort for a refund or dispute that other charge with your credit card company. They'll undo it.
If, on the other hand, the closing company never followed through in notifying the resort of your new ownership/membership and you're not in their system, then try to start again with getting someone to help you from their closing company TCS (Timeshare Closing Services, Inc.) or VININC or both. Here's what I'd do.
Send a polite, single email
explaining the BASIC facts of your purchase as simply as possible, with your
contract # and "HELP," both in the subject line. Something like:
- Date of eBay purchase: xx/xx/xxxx
- Contract # xxxxxxxxxxx
- Resort Name: xxxxxxxxxxxxx
- Buyer's Name: xxxxxxxxx xxxxxxxxxx
- Price and closing costs paid: $xxxx.xx
- Selling Agent's name
- What the resort says they know about your purchase
- Date, name and title of person who took your credit card info for MF payment
- What you want them to do now
- Thank them for wrapping this up quickly in response to this email.
Try to keep emotion out of it and stay focused on clear facts, as simply stated as possible. Remember, more honey than vinegar.

And as concise as possible.

Then send this email, CC'd to ALL of these people:
The selling agent(s) you used (email usually =
firstname@vininc.com).
The contract specialist who sent you the contracts from VININC.
The closing agent from TCS, Inc, their closing company (email = firstname.lastname.@tcstrust.com).
Email contact from the resort's website contact info or owner services.
You could also try calling your selling agent or closing agent again or asking for a supervisor. I'm sending you a PM with more contact phone #s and email addresses, of people who've been very helpful to us when we had a problem with a closing there. They were able to resolve it quickly once they knew what had happened.
I'd be VERY surprised if this doesn't get straightened out promptly - unless the
resort has their
own problems in owner services, which VININC can't help with. HTH! Let us know what happens in the next week or two!