A buyer cannot unilaterally cancel a transaction, even during the first hour (there is a special procedure during the 1st hour where in some circumstances a requested cancellation goes through if the seller does not respond in 3 days, but the seller can still reject that cancellation within the 3 days). A seller is never required to cancel at the buyer's request and is not obligated to respond. S/he can wait the 4 days and cancel for non-payment instead, or ship if you paid. You committed to buy the item and thus took it off the market and are expected to honor your commitment.
