ONTARIO NANNY AGENCY CHEATED ME HUGE AMOUNT OF MONEY WHERE I SHOULD MAKE COMPLAIN?

This is an unfortunate situation. You should report this company to Service Canada, if they still operate. Make as many complains to Canadian government institutions as you can, There is a slight chance they would be able to help in some way. Not sure. Try to contact also nearest Canadian Emby with request to help. I am not sure they will be able to help, but they might be able to stop this person from taking many form other honest people. This dishonest person belongs to jail.