I assume your references to "my company" and "they company" are to your employer.
Can I sue my company for the difference as it was misrepresented to the employees and no mention of the limit was in the enrollment guide?
Anyone can sue anyone for anything. Whether you'll win isn't apparent from your post. First of all, are you sure that you paid premium for $100k in coverage and not premium for $50k in coverage? If you are sure, how do you know that? Second, even if you did overpay, unless you have reason to believe that the difference in the monthly premium for $100k in coverage versus $50k in coverage times the number of months for which you paid the premium is truly significant, I don't think a lawsuit would be worthwhile -- particularly since such a lawsuit will probably result in you getting fired.
Your post is oddly silent about the conversation you had with the appropriate person at your employer regarding the discrepancy. For example, if your employer has a benefits administrator, did you talk with that person (or someone in HR, etc.) about the situation? If not, why not? If so, what response did you receive?