PM recieved

I recieved a PM from someone here on Friday morning which has made me very angry.
I had posted on the Ryanair site, giving my experiences of travelling with them as a disabled person.
I have posted on the subject before saying the same things.
The PM I recieved asked if I was really disabled or did I just make up a story so I could post on GN.
To all intents and purposes acussing me of lying.
It was not a nickname I recognised as most regular posters will know of my disabilites.
I am a bit angry and at the time thought of sending the PM to my lawyer.
I want to forget it but it has upset me.