I work in a small office and the office manager did not deduct the correct amount each month from my paycheck for my insurance. She is now asking for the additional money to be paid back which amounts to $22 per month for the past two years. Is this

I work in a small office and the office manager did not deduct the correct amount each month from my paycheck for my insurance. She is now asking for the additional money to be paid back which amounts to $22 per month for the past two years. Is this legal? Do I have rights that would not jeopardize my employment? Christine