Selling Unavailable Products Online

I purchased Xbox batteries online, and two days later, I received an email stating that my order had been rejected without any explanation. It’s disappointing that such a large brand would sell items they don’t have in stock or fail to mark products as out of stock when unavailable. To make matters worse, I paid R350, but the refund email only mentions R97. This is highly unprofessional. Despite writing emails to inquire about the reason for the rejection, no one has responded.