Superbalist unable to commit to their listed price

I successfully purchased and paid for a promotional item. I then got an email the next day from Superbalist that stated that my order is cancelled and the money was refunded, with a reason "Inventory error". I contacted Superbalist numerous times, because I didnt understand this reason - as the product is still appearing online today. Superbalist offered me another discount offer - but not close to the discount that I was getting on the day that I purchased the item. Superbalist was basically unable to commit to the price they listed on the item the day I purchased it, and this is unacceptable - as I am entitiled to the price that Superbalist listed the item at. Nonetheless, the customer service team fails to explain this to me, and for this reason, I will not be dealing with Superbalist going forward. Very disappointing!!!