The three pages you recieved "foreign filing" is your filing reciept. It provides your application number and other information about your patent application. It also provides a date that the foreign filing license was granted which is granted for virtually every application. The PTO checks your patent out before issuing a foreign filing license to make sure that their are no national security implications. If you file a foreign application before the PTO grants the foreign filing license your US patent could be invalidated. The rest of the three pages is just informational.

With respect to the "formalities letter" you recieved, the only formality should be that you did not pay the requisite filing fee. My guess is that you may have paid $75 when you filed the application, but the filing fees for provisional application went up to $100 prior to your filing. The formalities letter should inform you that you need to pay the rest of the fee, $25. You should not have to pay anymore than $100 total for you provisional application.

Since I am an attorney I need to include the fine print:
(The information provided herein is not intended to be legal advice, but merely conveys general information related to legal issues. The information provided is not guaranteed to be correct, complete, or current. I make no warranty, expressed or implied, about the accuracy or reliability of the information provided (although I'm usually right). You should not use this information as a substitute for retaining competent legal counsel (I usually research things better when I'm getting paid).
Furthermore, this communication is not intended to create any legal relationship between you or any user thereof and me.