Firstly, thanks for the information about this place and also Dongguan.

I wouldn't have any faith in reporting anything school related to anybody in China - apart from your embassy. I've been in China for 2 years and worked for 2 colleges (in Hubei and Guangzhou). I had problems with both which resulted in me contacting the State Foreign Affairs Bureau and my embassy. This is the only way that you will ever resolve a serious problem, like the school owing you money, because in my experience they only listen when you threaten them with something.