Øystein, that's an interesting story with the L. rosthornii. (!nd congratulations on your success!) It may have been an anomaly because of the juvenile state of the plant. I don't know. I am going to have to read up on this...
Anthony, I don't know that the seller did anything wrong that might give you cause for reimbursement. Am I jumping to conclusions here? Did he say they didn't need a treatment of any kind to spur growth? What makes you think the fault is his?