What are you hoping to do about this?
I'm really sorry but that is not realistic I'm afraid.
They are entitled to bar people for any reason they choose. This is not disability discrimination I'm afraid. It is certainly not perverting the course of justice.
Come what may, her employers have upheld her version of events and they are entitled to do that. One side is always believed over another in any dispute.
At the very highest point, she was rude to you. That is obviously something she shouldn't be doing but it is not actionable in law.
I'm very sorry but there just isn't a cause of action here even if the brewery had accepted your compliant.
Can I clarify anything for you?
I'm afraid your humans rights were not affected here and neither really were your consumer rights.
I'm also unable to see a disability discrimination issue?