I have the Explorer Club Visa Card - the one that costs $395 a year that's mean to include membership to the Red Carpet Club (now United Club). What they were telling me was that the Explorer Club Credit Card and Explorer Credit Card (one says Club, one does not, right?) are exactly the same.
That's where the confusion is - your use of the word "Explorer". If you have the Club Card, look at it - it should not have the word "Explorer" anywhere on it. There is an "MileagePlus Explorer" Visa card and a "MileagePlus Club" Visa card. If you have the latter, it's the $295 card with club membership. The former (The MileagePlus Explorer" card) has no membership. They are not the same. I think you're confusing cards/names and what they've been telling you.
Again, if your card says "MileagePlus Explorer" on the front, you do not have a club membership. You are confusing everyone if you say "Explorer Club Visa Card" - there is no such card.