Your lawyer is right. You had better file a lawsuit to get your salary back, and explain it to USCIS that the employer delay to pay your salary. Then, use premium processing for the H-1 transfer to get the result in 15 days. Mostly likely the H-1 transfer is still approved, but it may has no I-94 because you don't have the recent paycheck stub, then you just need to go to China to get the H-1 visa to come back to activate your H-1 status.
By the way, it is the employer violate the H-1 rule not to pay your salary, not your fault. So, you don't need to worry about it.
