Getting no where to convert miles to spend at a partner

I am livid this morning. I am been phoning Discovery a number of times for the last week to get my Cape Union Mart reward to purchase an item and after numerous phone call drops to them, I eventually could get the reward this morning. Cape Union Mart set aside an item for me while I wait for my reward, only to get to the store this morning to find that the item is back to normal prices, 3 times the amount what I would have gotten it on Friday. I am LIVID ... How do you reward yourself for healthy living if you are unable to get the reward when you wanna do so? I lost out on a great reward for a fraction of the price. Absolutely disappointing.