Dollar Tree review: The order was in paint and impossible to clean it

I have purchased from the company Greenbrier International Inc. The order and the process of the delivery was fine and without any delays. However, the order was full in paint and I needed to clean it with water, but I have tried couple of times and nothing helped. Also, the company told me that it wasn’t the reason, so they refused to change the order. How can I clean it and is it ok that the company has refused to help?