I have signed an agreement with my employer for 12 months. Before 12 months, I left company by giving notice period as specified on offer letter. He has send notice through lawyer which states business loss, H1B visa fees and attorney fees. He claimed business loss as (no. of days left in 12 months * billing rate) - salary paid during that period (days left to be completed for 12 months). Could anyone advise me what should be done?