One more time people...

1) You are not required to accept or pay for something you didn't order. If you send it back unopened with a note stating that you don't want unsolicited items you don't have to pay the postage, and they will take you off the mailing list.

2) The Field Test Program is open to all members, which means that you're in line with several hundred thousand others. You don't get sent items just for being a member, you have to fill out a Field test form and submit it, even after receiving a test item if you want the chance to test other items. Learn the rules and follow them.