There isn't a rebate form for the gift cards, HWSC automatically credits your credit card account at the beginning of the NEXT month, so you have to stay a member long enough to receive your credit. I've read that depending on when you joined, you could receive your credit during your free trial. Depending on how many GC you purchase, you can still get a very good deal even by paying the fee one or two months while you decide what GCs to purchase.
The GCs are just like the ones you purchase in the stores, with no expiration dates. However, some of them do include a clause similar to this - To cover administrative costs, a $2 per month dormant account fee will be deducted from the balance after 24 months of non-use. This is from the Toys R Us card, and it is included on GC you purchase at their store also.
I joined in mid April, and made 8 purchases from them, including meal vouchers and GCs from Kmart, Target, Toys R Us, Babies R Us (the TRU & BRU cards are the same & can be used at any R Us store), Sam Goody, and Chuck E. Cheese's. I received every purchase in less than a week, every credit was applied properly, and I received the $10 rebate very quickly. I'm going to cancel for now, but plan to re-join next year for more Target cards.