Kirsty
Very pleased for you,
I'm afraid there is no guarantee of an award with a PBA but there are only two reasons why one would be done, they have sufficient, relevant information to make a recommendation to the DWP or the there is no evidence of a disability in the first place, given the trouble you have had getting a PBA I think it very unlikely that it is the second reason.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems