This has happened to us all, so can appreciate how frustrating this scenario can be.
However, at Plugin Boutique we frequently offer flash sales and other promotions which are subject to change. Because of this, we cannot offer credit on products which were purchased before a sale/or whilst on a separate promotion.
You can check out our Refund Policy here for more information.
If you haven't found a solution here, feel free to submit a request to our Customer Care team or speak with us via Live Chat.