Dissapointing when things go wrong

I have been satistfied with Fireworks Crazy before but this time they forgot to add the items from their promotion of 20% extra. Easy mistake but they offered no compensation other then the same deal of my next order (which would be next year) and I don't really want to use them again so I'll never see that money now. Mistakes happen, naturally, but the customer should not bear the brunt of them.