Some mistakes here as I see it:
- User inexperience. I have little doubt that the reason your grinder didn't work is that you choked it with coffee. This is a common trap for beginners
- You chose to save a little and forgo the option of having a local business support you on your learning curve. The issue could have been solved in 2 minutes via email or on the phone.
- The company which sold you your grinder actually offered a refund on goods which were not defective. What should have happened was that they should have charged you for return freight
- PayPal came to your assistance when in fact they could have contacted the seller and found that you had returned a perfect grinder. These episodes will ultimately push fees up as you should not have been entitled to a refund.
Rather than suggesting that everybody purchase another brand, I think you should be feeling embarrassed that your rant has pointed out yet another common episode of a new user blaming the tool rather than first looking at technique and seeking assistance.