Indian Commerce Clause of the Constitution??

Hello,

I was just looking through the documents that I got from Cash Call regarding my letter to them notifying them that this loan is illegal.

I found this:

"Governing Law: This agreement is governed by the Indian Commerce Clause of the Constitution of the United States of America and the laws of the Cheyenne River Sioux Tribe. We do not have a presence in South Dakota or any other states of the United States. Neither this agreement nor the Lender is subject to the laws of any state of the United States of America. By executing this Agreement, you hereby expressly agree that this Agreement is executed and performed solely within the exterior boundaries of the Cheyenne River Indians Reservation, and soverign Native American Tribal nation. You also expressly agree that this Agreement shall be subject to and construed in accordance only with the provisions of the laws of the Cheyenne River Sioux Tribe, and that no United States state or federal law applies to this Agreement. You agree that by entering into this Agreement you are voluntarily availing yourself of the laws of the Cheyenne River Sioux Trive, a soverign Native American Tribal Nation, and that your execution of thei Agreement is made as if you were physically present within the eterior boundaries of the Cheyenne River Indian Reservation, a soverign Native American Tribal Nation."

My questions is how I can pursue this as being an illegal loan when this is in the contract I virtually signed before getting the loan? PA department of banking said this loan was illegal and I have also seen it throughout this website, as well. But if this is in the contract then how am I not bound by that? I want to pay off this debt for the rest of the principle and not pay the interest - based on it being illegal in my state. But this has now confused me.

Thank you!