Trade is a trade?

I contacted this woman about trading my 10 yr old well broke QH for her 2 yr old filly. She decided she wanted it to be a fair trade and threw in a 4 yr old filly that is green broke. So my family did all the hauling 3 1/2 hours to her home got there at 10:30 on Friday night and made the swap and drove most the night to get home. Apparently they tried riding my old horse Saturday bareback and she bucked... she NEVER bucked the entire time I owned her and I contacted the previous owner to us and she never bucked then.... we are accounting for well over a year if not 2 yrs of owners. This mare was used for beginners and children to ride when both of us owned her. So this was just this past Friday night until today. Yesterday they decide they want their horses back and are bringing my old mare back. What? I'm happy with the 2 I have to train. I've had to move them to another location because I'm afraid (due to their statements) that they are just going to show up and swap them out without me being there. What would you do? I'm open to suggestions. They have to be doing something wrong with my mare or maybe just as simple as not having given her enough time to settle in with strangers.
Thank you!

Regardless of whether there was money involved there should have been a receipt for the trade. Unfortunately not everyone is honest and this could turn messy. Do you have some emails to back up the agreement if you don't have a receipt? If they show up and cause trouble call the police asap.

Yes, yes and yes
I hope things work out for you without too much strife.

Has the horse ever been ridden bareback before? If so, did the horse act up then?
I had a mare that was brilliant under saddle, but hated being ridden bareback at more than a trot - I guess some of them are just like that. Or I have a pointy butt....
I would round up any sort of paperwork you had between you. This is the reason I always state "Sold as is." on my contracts.

maybe you should try and get in touch with them and suggest they do a bit of bonding with your old mare before they throw themselves on her bareback and then decide they don't like her ?

I know you want to keep the two you have but on the other hand I don't know that I would want my horse to go to someone who would want to get rid of it after one buck. Even though you and the former owner never saw the horse buck it is 10 and you are only accounting for 2 years of its life. I agree they probably rushed the horse along instead of letting it settle in. So what kind of horse people does this make them?

Very possible someone hopped on the horse gave him a swift kick and hauled on his mouth. (who knows) Bottom line is they don't want your horse or don't want to give it a chance so I would say safest thing maybe to swap back. Otherwise it could get really ugly and I hate to think what might happen to your 10 yr old QH.
Just my humble opinion.

Good point.

Well, do you have any results on the out come?

hmmm,, hope its not one of those hit and run posters

I know a trade is a trade but they did contact you within 24 hours and told you they were not happy. If you bought a car and found out the next day it wasn't what you wanted wouldn't you want to take it back. I'm not saying you miss represented the horse, I'm just saying they fill they didn't get what they expected.

I think you should try to work something out with them.