As a shareholder in the company (I am presuming you are here) you will have been given or have the right to see the Articles Of Association which set up the (Management) company. If you don't have a copy then you can ask the Company Secretary to provide you with a set. These should lay down all the rules that govern the way your company handles itself and its business.
AS far as I know no motion to dispense with an AGM has been discussed/passed. Unfortunately the more I take an interest (which I should have done long before now)the more I find wrong with the running of the company.
I do appreciate that directors cannot keep asking for permission to do things but I feel neither can they just bulldoze and ignore the other shareholders.
An EGM can generally be held at any time, subject to enough notice being given to all shareholders. An AGM can only be held once a year and is usually held to present the accounts and to answer questions on them for the previous year and to highlight plans for the forthcoming year(S). A couple of years ago legislation was changed which meant that Directors of a small company like a residential management company do not have to hold a AGM each year, but they must still provide accounts to all the shareholders. You should approach the Managing Agents too (if you have any) to ensure that you have all the accounts to be able to question the directors who are obliged to answer your questions whether at a meeting or not....but I am not sure how to force them to hold a EGM to discuss general running issues. I'm sure much of what I have said you already know but I hope it all helps.