For me, the worst is that I have worked for them for more than 4 years and that I have put my effort into learning their academic product.

I'm sure you have grasped the ins and outs of teaching GAC efficiently to Chinese students.There's no substitute for experience when it comes to teaching courses such as GAC.

Now, that I know it well enough to facilitate many of their subjects, I am forced to leave as I had little choice in the middle of my contract but submit my resignation letter at GAC Chongqing. Applying to some other GAC centers, I have discovered that they do not want me.

That seems to indicate that the GAC providers here in China do not consider the employment of the best and most experienced teaching staff for their students as one of their main priorities.I suspect that doing so is overridden by their overwhelming desire to dupe and milk the rich.
Another example of their lack of professionalism worth mentioning is that they will knowingly break the Chinese visa regulations by employing louwai without work visas.In the case of one GAC centre,it has come to my notice that both FT's initially employed there had tourist visas while teaching for about a month,and after one of them left,his replacement,who would also be working illegally there for a few weeks on a tourist visa would be no less a person than a Stanford graduate and former senior director of an American multinational.How low will people stoop to make money here?The old adage 'when in Rome do as the Romans do' might very well apply!But the new Rome is China,a country where there is more often than not no rule of law.

GAC Centres here are all probably dodgy outfits after a quick buck,best to be avoided by rich Chinese students and prospective FT's alike.