I have complained and the same kind of stuff is still happening, perhaps its time to bring in a more squared away company to look after gate guard duties and so forth. I'm not convinced the commisionaires are completely up to the task. I know some are but alot are not.
The Corps of Commissionaires has right of first refusal on security contracts so in order for a "company" to be brought in, they would need to be "unwilling" to fill the positions and pass on the call up. Note I do not say "unable" as, in my experience, they will fill the post with someone on life support before they admit they can't fill it. Some places I have been at, it has been horrendous. One place the Corps did not have enough personnel to fill all the contracts so rather than let the position go to another security company, they had their pers take "leave" from established positions in order to have them work the temporary post they didn't want to admit they couldn't fill.
One other point. The Commissionaires do not "work" for anyone in the military chain, including MPs. They are contractors who are contracted to provide a service. It is up to them to provide the service within the terms of the contract they are hired via. The best we can do, even when someone is obviously unsuited to the job, is to file a complaint with the site manager and request they member be removed from post. While this normally happens, it is not unheard of for that individual to reappear doing another job several months on...