I work in goverment social policy and your PCT could end up in a lot of trouble over refusal to give Xenical!
The Department of Health have issued an order about how obesity must be treated by GPs. Xenical and Meridia are included in that order, they're the only weight loss drugs that are.
The documents are all on-line, here's the link if you get very bored [url]http://www.dh.gov.uk/PublicationsAndStatistics/Publications/PublicationsPolicyAndGuidance/PublicationsPolicyAndGuidanceArticle/fs/en?CONTENT_ID=4134408&chk=Sq/wNd[/url]
Anyway... if someone were to challenge the PCT in court about not prescribing Xenical the PCT would lose. I'm not suggesting in a million years that you so this, the time and money it needs would be pheonomenal, but for reference your PCT are in the wrong.
I buy my Xenical online for about £65 a month, it's not cheap but it is the cheapest I've found.