This is a conundrum for any company holding a sale.
Unfortunately we would be morally obligated to apply the same rule to everyone if we refunded one person's discount, and we simply do not have the resources to manage that on a large scale.
No matter when we announce a sale, someone will almost just have bought a licence at full price or with a smaller discount, so there will always be a customer in your position. We assume you accepted the price the software was offered at when you made the purchase and hope you can accept our point of view?
Our only real alternative would be to never hold a sale.
May we suggest you sign up for the free IPD workshops and get some extra value from that?