This type of "promotional" free trials have been used before and have been questioned by authorities such as State Attorney Generals. I guess BUYER BEWARE was created for this sort of "deal".
One must wonder if a product is truly a GOOD product and does what it professes to do, does the marketing need to use such "sneaky" methods.
I plan to try to return the second shipment and end my "membership" as well as get credited for the reasonable (?) price they charged my credit card. If nothing else I will cancel my credit card and get a new number just to get out of this mess.