Has anyone had experience with business brokers who blatantly lie?

Has anyone had experience with business brokers who blatantly lie? I've had several experiences with brokers who have lied during negotiations. They say something like "the seller accepts your terms, and we are signing the LOI today" and then the very next day or a few days later they send an email saying "we signed an LOI with another buyer, thanks for your time".

This has happened on several occasions and I'm in disbelief how brokers can just lie and act like it's a normal way to do business. No remorse, no shred of honesty and It actually works against them to not inform a buyer that there are other interested parties.

I think the industry is full of these cowboys and it's sad and frustrating to go through this time and time again.