So, I'll start by stating I have no clue what so ever.

BUT...I would caution you to first take a moment to decide how much time, energy, and effort you want to invest in this. Is the 2 week deposit worth the stress and energy it will take to figure it all out. If not then it might be easiest and best for you to just return the money and wipe yourself completely clean of them. They are clearly taking this very personally and this isn't about them getting their money back so much as they feel you have rejected their child and they want to make themselves feel better by winning this.

If you truly feel you want this deposit (and I agree that they agreed to it, and you invested your time and energy into this family) BUT sometimes the gain just isn't enough to counter what this could become.

I think you lose either way here. You fight to the end to keep the money or you return the money and let them "win" so in the end you might come out best by taking the approach that means less stress and frustration on your part (as much as I admit it would kill me to return it to them)!

I feel for you...but on the bright side terminating care means you won't have to put up with them long term!