Hard to send it back because there is little proof of how bad it is. First crap bag I had, the dealer reckoned either the resin vesels were knackered or my ro. It's happened to several people I know. I think Gardiners worked out how to avoid the bad stuff. Can't remember how but I think there were two different importers so they could trace the rubbish by using the batch numbers.
My batch number is 722137 if you've got any with the same number then bad luck!