I think I see what has happened.
You have changed the price from $4 to $5 & now it looks as though I haven't paid enough. You can even see by your store page that it hasn't been updated correctly. You page says pay $4 or more to get the Unreal map pack. But at the checkout it asks for $5.
Can you please send me a google drive link or something to rectify this issue please? I can prove I bought it.