I have had the same experience of asking my lender to lower my rate after paying faithfully for some 8-10 years. Asked for a reduction to a rate actually higher than market. They laughed at me. I ended up refinancing with another lender at a lower rate than I had requested. However I did have to pay closing costs.

PS - when I bought this house Jimmy Carter was in the White House and my interest rate was 13.75 %. Still here after 28 years and not paying nearly as much in interest rate.