Eric, if you would like, you could send me the original closing cost estimate or GFE and the new one and we can compare where the differences are and if it seems legitimate.
1) you should have received a GFE within 3 days of applying
2) If the closing costs changed or the APR changed by more than .125% , and Mortgage Ins Premium would do that, the company needs to redisclose immediately and not close for 3 business day after that disclosure to allow you to review the documents
3) If it is mortgage insurance premium, FHA increases the loan amount to cover that so you out of pocket, cash to close should not have changed.
It sounds like they may have made a mistake in disclosing this and you do have some recourse here. I can help review these and you also should contact an attorney or the owner of the mortgage company and express your concern based on my comments and see if they are interested in resolution.