They are not allowed to discriminate against you because of a disability. Maybe you should look for work in big companies who will have proper disability policies, such as the NHS- in fact, any big company! Are you sure this is why they don't want you? It might be asking an interviewer for feedback after the interview. They can't say this is the reason, anymore than they can say that it is because you are too old or too fat, but they could give you other reasons which you are not aware of.