DealMax Unauthorized charges on my credit card for membership dues Internet

We have absolutely no record or recollection of subscribing to this service.  We never received any information, membership card, etc from DealMax.  Obviously, we found no record of sign in user name or password to their website.  We keep a very detailed and organized list of this information.   Somehow, we just missed the DealMax charges, which had been going on for several months.  It is shocking and totally unknown to us how these items went by unnoticed.    DealMax said that the subscription was done through the internet, however, no other explanation or proof was provided.  We not knowingly subscribe to this kind of service, which appears to be a discount type promotion for several major stores. In this case, we have absolutely no information regarding DealMax. The credit card company has agreed to further investigate the matter.