What is the best way to deal with unethical REA in WA state?

[Eddie Medina De Leon]

As I was selling my house, the seller complained about damage floor. In order to close the deal we agreed that I would fix the floor. The buyer and agent wanted a guarantee (10k) They will keep the money if I didn't fix the floor. In order to fix the floor, using my insurance, I needed access to the house and photos for an estimate. They decline to give me access, the REA stop returning my calls and texts, and they keep the money. Once he finally did, he behave in a unprofessional manner. I contacted his local and regional supervisor to no avail. I even contacted Home corporate. I know the money might be gone, but I can't in good faith walk away knowing that there is a REA taking advantage of people.... Any suggestions?