Prosvent scam company, won't honor their money-back guarantee, nationwide

My brother got sucked into ordering Prosvent, some type of herbal remedy for prostate problems.  I'm not sure whether he realized at the time that this was a recurring order, meaning they automatically ship every 2 months, charging his debit card $107 each time.  He died sometime in the early a.m. hours of Feb. 8.  Later that day a package came from Prosvent.  When I realized what this was I promptly called Prosvent to cancel.  I also asked to return the sealed, unopened bottles in accordance with their Money Back Guarantee printed clearly on the packing slip.  I explained that my brother had died so had no use for these pills.  The phone rep rudely informed me that the guarantee was only valid on the FIRST order, and that future orders were not covered.  That's NOT what the packing slip says!! He went on to tell me there was an "arbitration agreement" that spells this out. I called his bank (Chase) but since it was a debit rather than credit card order, there was nothing they could do, other than to cancel the card so no future charges could be made.