PMI

I too, am having difficulty cancelling PMI. We've had the loan since 2004. A couple of years ago, we paid to have another appraisal completed of our home and it appraised at 30K more than the original value (250K versus 220K). This placed our equity at the 75% at that time. They wanted us to prove the increased value of the home by providing receipts of home improvements that totalled the 30K difference. I did this and they still refused to remove PMI. Now, 2 years later, our LTV from the original value of the home is at 75%. With the drop in property values in the area, I doubt that the home would appraise at the original value, and the mortgage company is insisting on another appraisal (at our cost of $150). Can you cite federal laws that require the elimination of PMI at 78% so that I can use this on my letter to GMAC? I've already turned them in to the comsumer protection agency. OUr payment history is impeccable. Up until recently, we were paying an additional $220 per month towards the payment in addition to being enrolled in the equity excelerator program making bi monthly payments.
We continue to pay bi-monthly as we have seen a huge decrease in the principal amt once starting this.