A little benefit of the doubt; I could easily see how a seller would have moved a trip date from say early May to early August with all that has happened. Sure, they should have told you, but things have been pretty crazy. A couple of questions;
- What is the Use Year of the contract?
- Were you aware that the points being used by the seller in August were not included in the contract?
- When did you intend to book your first trip?
Reason I ask is, for all intents and purposes, you are not going to use the contract before August 2020 anyway (could take a chance on a June or July reservation I suppose). If you did not plan on booking a trip until August 2021, you will still be able to do that. If you planned on going in May or June 2021, that's a problem, in that you will miss your 11 month out booking window, and that will be crucial in the next year or so. As long as it's a Feb or later use year, you will still be able to bank points with that delayed closing date.
Now, if they didn't tell you they would be using the points, that is a BIG problem! You should not be paying 2020 MF's for those points NMW.
If you've thought through all of the above and it doesn't affect your plans too much - maybe just let it go. Points are points in the grand scheme. Yes, kinda shifty on their part, but pretty easy to move on, so why not do that? You'll have your own cash for the remainder of the contract $$ in hand until it closes in August and that is not a bad thing.