This type of mould is invariably caused by a reluctance to ventilate a room that demands it; usually because of ineffective or costly heating needed to compensate 'letting the cold in' when the desired effect is 'letting moisture out'.
That the Stn Cdr has no direct influence on remedial action does not mean that he cannot apply pressure when a genuine complaint is staffed correctly and I would suggest immediate CoC in the first instance supported by photographic evidence. If this proves ineffective, the CoC are almost certain to share the frustration, although I have seen evidence of the contemporary Estates system being royally anal when a Chief Tech refused to accept a disasterous FMQ. SSAFA & Padres assistance is within the rights of everybody from the onset of the complaint as is a Regional Health Worker/Social Services if young children are at risk.
Once these avenues have proved inefective, that is the time to go nuclear with Press and MP letters. As has been suggested though, a reluctance to ventilate or correct with elbow grease could open up a world of hurt. The problem is that once mould has an appetite for a location, getting rid of it is a serious problem that usually involves industrial standard dehumidifiers and excess heating settings that demand windows being open, and the associated costs.