OK, I have no idea if anyone else has done the legal aspect, frankly I can't be bothered and haven't the time to be reading the whole thread.
He, as a service provider, has a duty not to discriminate against you due to your disability (bi-polar). However, he has provided a service, what you have to do is prove that the way he did this is unacceptable and discriminatory.
Could you potentiall do this? Yes, I don't know the medical side but you're going to need an expert report, potentially two if the first one is unfavourable, to pay an expert for court and, finally, a shedload of lawyers' fees. The likely payout is pretty low, almost certainly not enough to cover the costs of the above, or indeed close to. A court case would be a very expensive way to prove a point.
An alternative is to write to the Equality and Human Rights Commission and get them involved.