E-Bay purchase?

[irv]

I recently bid on a low value 52 Topps card on E-Bay and actually won it last Friday. ($11.00)

When I was looking over it again, I noticed a "poor" comment beside the title/description that I didn't originally recall seeing? I assume the seller can edit their ad anytime they like? Not suggesting they did, I just don't recall seeing it?

Immediately after I won the card, I requested a pic/scan of the back of it, to which I received no reply? I sent another 3 messages and still no reply??

Yesterday, I finally received my invoice from E-Bay to pay for this card, which seemed late to me?
Anyways, I wrote the people again, for likely the 5th time requesting a back pic/scan, info about the card.
I finally received a reply today which stated: "If a back picture is a condition of you paying, you need to say that before you bid, not after"
The reply still didn't show/have a scan/pic of the back of the card.

I am looking for some advice here? Am I obligated to pay for this card simply because I won it even though, after ignored multiple requests for more info about it went unanswered?
The fact they finally replied today but still didn't provide a pic/scan of the back?

Being fairly new to all this E-Bay/bidding stuff, it's likely a rookie mistake and something I'll have to learn from, but, like I originally stated, after not seeing the "poor" comment in their title, 4-5 message requests going unanswered, still no pic/scan of the back when they finally answered, leads me to believe something shady, unprofessional is going on?

I would appreciate any info you guys can provide about this situation I am in.

Thanks