Do not be fooled by money back garauntees in listings. On their own, they are worse than useless.
I recent ly purchased a product from ITSMYLIVIN which was listed as having an unconditional full refund garauntee, should the product fail to work.
I tried to get my money back under the garauntee, without success, being told that refunds were not offered.
Turns out that ITSMYLIVIN is a reseller and had just copied the manufacturers blurb.