Midwest Loan Services, Inc. Mortgage Complaint

Midwest Loan Services, Inc. Mortgage department,

Conventional fixed mortgage Loan servicing, payments, escrow account California

My mortgage LTV is currently 77 % and the mortgage service company will not remove my PMI. They have sent a new letter stating I must have a 75 % LTV. Last year, when the LTV was at 79.6 %, I sent a written request to remove PMI and they denied my request but did not explain what specifically disqualified my request. This was a refi but I 'm not seeing anything in the rules making it different from an original purchase. If the law says PMI must be removed when I reach 78 % LTV, why can the mortgage service company keep charging me this fee?