hi i agree they have not treated you fairly and Dennis is right to say see a lawyer (ignore the fact that i am one no vested interest in this!)
you should be able to take them to a tribunal under the DDA they will have to justify why you were terminated and prove that they were not justified in doing so, ie you work on chimney stacks and were not safe to do so, but even then they have to try and find you something else to do
they sound like a right bunch of arses :twisted:
log onto either the law society website or legalservices.gov.uk to find a lawyer in your area Legal services will help you find a specialist legal aid lawyer and even if you don't get legal aid they will know what they are doing (there are not many of them around these days but worth it for the specialism)
remember you only have about 3 months from dismissal in which to lodge a claim so you need to do it asap
good luck and keep us posted x