They are just going to use their 2nd VA loan to buy their next one while this one is tied up. 

Their insurance has asked me to return the month's payment for the remaining days of their rental (Unfortunately, I did not have a cancellation agreement).I am unsure how to handle this situation, especially since I couldn't fill the majority of the rental dates and had to offer discounts for the days I did manage to book.

You need to understand that given your situation the asset and operational impact must be absolute minimal, lowest risk exposure possible.

If so, that isn't everyone's situation (and is also not mine).

**They adjust on the fly & don’t rely on scripts- Every seller’s situation is different.

For context, I will be assuming his VA loan at 5.1% and he will be doing seller financing for the remaining equity and sale price. 

It sucks being a situation where you want to unwind a sale or have to lawyer up and go after the seller.

Good luck with your situation. 

There will be many situations where you can help a homeowner save their home -  however, in other situations they just want to sell quickly which provides a wholesale, fix/flip, buy/hold opportunity for you. 

@Summer Shelton yes, FHA loans do allow this but make sure you speak with your lender about some of the trip ups from these loans.