Multiple W2s from same employer with total social security withholding is way more than the limit? Employers doesn't want to fix it

Hello I received 4 W2 from my previous employer and all the W2s have the same EIN number and the total amount of social security withholding is way more than the annual limit. 

Employer explanation is: The W2 are issues from payroll consolidator which show the same EIN number however the actual work is for subsidiary companies which have different EIN. They claim if they give me a refund or updated W2C then they will break the tax withholding laws since it was  withheld under different EINs. 

How to resolve. Please help.