You shouldn't need a lawyer for this. File a complaint with your state insurance commissioner. They exist to settle disputes like this and can be an advocate on your behalf.

I've had employers who have and employers who haven't. And of those who did, the amounts have varied; my current employer only contributes $650/year, but it's been as high as $1,000.

At least the ones who haven't contributed have offered the plan with no out-of-pocket premiums.