sporter vs Wells Fargo

A few months ago I was looking over some paperwork and I realized that my mortgage company should have dropped PMI over a year ago. PMI is like $45/month and over a year it adds up. So I called them in Feb and was like "hey, I shouldn't be paying PMI". After a few days they got back to me and agreed to eliminate it. I was like "ok, that was easy". Well, it wasn't that easy... I get my next bill and I was still paying PMI. WTF?! So now I'm annoyed and I start a new round of phone calls. First they deny the original finding and they argue that I need a new appraisal. I'm not backing down at this point... I want PMI removed retroactively. I've had about 10 phone calls with them in the last couple months but finally today they wised up and removed PMI retroactively back to when they should have. I had them credit that amount, $625, to the principal. Sweet. Victory for the little guy!