These people are unbelievably rude... As a first time home buyer, we were told that 21st mortgage was the way to go by a local realtor. Should have known when the interest rate came back at 12.5%, but we figured it was a penalty for not having much credit out there. Almost immediately they would start calling a few days before our loan was even due, and then if we were not home or did not answer our phone, they would start calling our references. ridiculous! In 2011 We were in a car accident and were unable to pay our payment on-time, I asked them if they could re-age our loan and let us tack that months payment onto the end of our loan because my husband was out of work for a month. They replied that they never do loan modification and that we needed to call family or sell some of our possessions to pay. Needless to say, we ended up paying late and They have been harassing us every month. They call family and friends and tell them lies, they have even called my husbands place of work and have said some downright evil things about my husband. We are ready to just leave our house and let hem have it due to their behavior. DO NOT DEAL WITH THIS COMPANY!

You might want to know how loans work before signing any sort of contract. Request an amortization schedule. Here is a helpful link you can obtain by using a website called 'google' and searching for 'amortization schedule':
http://en.wikipedia.org/wiki/Amortization

Since the interest portion of your monthly principal + interest payment (which will never change throughout the life of your loan) is calculated from your principal balance, you are paying much more interest compared to principal at the beginning. This is because your initial principal balance is at it's full amount. Thus, your loan amortizes much more slowly at the beginning of your loan, but you will gradually be making a bigger payment toward principal as the years go on because your principal balance is in fact decreasing. There WILL be a point when the majority of your monthly payment will be more than your interest portion. You can see when this will occur by looking at said amortization schedule. Imaging

In closing, it is not surprising your principal balance only decreased by $2000 in 3 years. Your loan is amortizing as intended and is a result of a simple mathematical calculation.