Sorry to hear about the bad experience! T5 security is generally a nightmare at the moment (whole separate thread running) as they've increased random checks and changes approach to reviewing scan anomalies after supposedly failing an audit.

There'll be a couple more opportunities to air complaints as well - Pucci had her MP complain, and when the inquiry into a third runway is up an running it could be an interesting way to vent (just think of several hundred letters being released as part of it saying BAA are useless at security, may get some traction...)