Mak
What is the purpose of your posting ?
so you get refused transit through the man control zone ,so what, would you be posting the same line if you were not allowed through the Gatwick Ctr if they were busy.Read and learn what Bodo has to say about the Low Level Route.
Pre plan you flight better ,assume the LLR and anything else is a bonus.
Dont get airborne and expect to go where you want to go.
Dont slag off ATC when you dont get what you want especially around a major International airport.