I paid a mere $15 on Amazon for a stainless steel reusable coffee pod alleged to suit my K-Fee Preferenza machine. It doesn’t fit, its 29mm tall, needs to be 28mm to fit properly in the machine. Diameter is OK, though.
I instigated a return/refund with the seller whose condescending response was quite insulting.
“Considering that return will take time and money as for this issue
we will issue you 15% refund as a disocunt could you keep the item?

waiting for your reply.”
I responded that the item is completely useless to me as it doesn’t allow the locking handle to depress fully & is unsuitable & unsafe.

15% of $15 is $2.25.
Cheap scum. Own up to your responsibilities under consumer law, areswipe.