Spirit Halloween

I do NOT understand how a company which is open online 24/7 says I can not return merchandise I bought less than 24 hours ago and I have receipt but can not get a refund. I will NEVER shop there and that was my first experience with them! My kids had to settle due to low inventory then when they find what they wanted somewhere else I can't return. What if I hadn't bought it went to look for others somewhere else and then come back and costume is sold because if low inventory in first place.