Thank you for expressing your concerns – perhaps I can shed some light on this for you. We have a very low return rate on our website, as the majority of our inventory has over 98% compatibility in the United States. To further illustrate that point, we have over 50,000 5-star reviews on Amazon with an average rating of 4.5/5 on our products. So the compatibility issue you had is very uncommon, and I am sorry for your experience.
The shopping cart feature that you mentioned was not an attempt to charge you in advance for a return label, but rather a 3rd party Shopify tool that provides an optional Amazon-like "unlimited returns" experience – it is more like insurance, covering all shipping and replacement costs for loss, theft, wrong delivery, exchanges, returns, etc. Amazon charges monthly memberships for Prime, while this service was just an optional $1.99 offer at checkout.
I hope that helps clarify it for you. Please do not hesitate to reach out to us directly if you have any further questions or concerns. Take care, hope to hear from you again soon!
Sincerely,
SnapPower Support