Halloween is almost here.

But some Amazon Prime customers say their spooky holiday plans are ruined thanks to the online retailer.

Amazon's Facebook page has recently received numerous comments from customers who claim their membership perk of ultra-fast shipping has been missing the mark.

Amazon Prime members pay $99 a year to enjoy faster shipping options and other exclusive offerings.

Many members weren't worried about ordering their Halloween costume last-minute because of their Prime perks.

An angry parent wrote a Reddit post this week about having to find a new costume for her son after Amazon Prime didn't deliver an order on time.

When I ordered a costume for my son on 10/18, it offered Prime two-day shipping. Strangely, when I got the order confirmation, it was scheduled to be delivered today, 10/26. So I tried to update the shipping preference, but the scheduled date stayed the same. Last night, it said it hadn't shipped, but was scheduled to arrive by 8pm tonight. This afternoon, I get the email from Amazon that says there is a delay and the costume will now arrive on 11/2. Obviously I cancelled, but now I have to run around with my son and try to find another costume. Thanks for the false promises Amazon!

The post was followed by other sub-posts claiming the same issues.

how do you contact them to complain to get the free month of prime/refund? I ordered 3 items with 2 day shipping. 2 came and the main part of my costume won't arrive until after halloween!

Scrolling through Amazon Facebook posts reveals claims from more customers who say these delays have been going on before the flood of Halloween orders.

The Amazon website states that not all shipping speeds are available for all items and addresses and that if an item is out of stock, the shipping method time starts when the item is made available to ship.

The website also advises customers to check the ordering cut-off time shown on the detail page to see what shipping time applies to their order.