Social exclusion

Im a 63 year old, high functioning lady with audhd. I was a member of a local amateur drama group for over 20 years on and off. There a young man there who is treasurer, actor, lights, sound, tech, committee etc. I had call to go to his house and noticed a costume belonging to me that I had thought taken by another group when we had joint storage. So I was surprised to see it and said I would love to get it back. I messaged the theatre group who then had it and they were fine and said yes of course just take it. 
I was then told by this man that I had upset him as he had a good liaison between the two groups and I had created friction. I apologised and said they had seem fine. 
a little later I lent this group a costume and they kept it without return saying they had originally paid for this 18 years ago but in fact I had given the cash to the treasurer at the time so it belonged to me. They agreed to give it back. I then received an email saying I had upset this man and was now barred from membership!! I went into meltdown and was emotionally traumatised by it all.i tried contacting man but he hung up and then blocked me on all social media. 
A year on and he appeared doing lights at the theatre I am now at and happy at, I tried to speak to him but he just blanked me. 
I was happy to try and resolve the matter but he refuses as he says Im just a mental ***! It's been very upsetting as all my other theatre friends love and support me... is it legal to exclude someone with autism without making an attempt at reasonable adjustments?