Christmafy review for WC Fulfillment Print on Demand

This app is a scam. When using the app to sell cheap t-shirts, I made a custom t-shirt design with front and back. When making the product, it said it would cost me 10.99 plus 3.99 for shipping in the USA. But when I placed an order to test the product, it was an extra $5 because I have print on the back (which was not on the product page creator). So my cheapest product was costing me, $20.41, I found out that it was an extra $5 because I checked their website and they were false advertise the pricing. Honestly, I might sue.