I have to agree that its wrong for an individual controller or unit to decide to apply their own rules in class "D". The rules for class "D" are clearly defined and one should be able to plan to use CAS subject to common sense and not at the mercy of an individual's whim. When the initial Airspace Change Proposal is submitted for class "D" the CAA would judge that the proposal should be accepted on the basis that VFR can reasonably expect to transit under class "D" rules. If the individual controller or unit decide to breach the rules under which the airspace is established the whole section of airspace should be withdrawn and the ATC unit should be forced to resubmit the whole ACP again, including the environmental considerations.
Personally I would write to the SATCO or manager to complain and ask for an explanation in writing and if the answer was unsatisfactory forward the correspondence to the CAA siting a breach of the ACP.
Many yeas ago there was a controller who stated that he would not let anyone other than commercial in HIS airspace ("D") regardless of number of engines or whether they had a transponder, even if there was no traffic and none expected. I understand that the CAA did explain the error of his ways to him.
There is nothing to stop individuals from writing to the CAA or the ATC unit and asking for them to investigate and have the tapes replayed. It might be that there was some traffic on another frequency that made the crossing too difficult. I seem to remember that if transit is refused the controller is supposed to give an estimate of how long it will be till they can give the clearance, was this done on this occasion?
bb