Expired Converterbox Coupon

In the beginning of July 2008, I requested two converter box coupons by phone and was approved. I received the coupons in hand on August 22, 2008 and went to the local Wal-mart to purchase my converter box and when I opened the envelope and retrieved the coupons, they had expired on 08-06-2008. I called again to inquire about replacement coupons and was informed by a computer that I could not receive any more since I had already received two. Don't you just love the way that our Government is looking out for the American public!