No refund took place. He's lying. He didn't even try to contact me, and if you look at the originating addresses in the problematic transaction, their balance is still 0.

Why is this psychopath allowed to operate here and keep scamming people? Why aren't obvious criminals and scammers banned?

I PMd mr. Buckley again and informed him of my plans to alert his local law enforcement authorities in Dublin, should he fail to pay me back by Monday night.

This is a well known scam.

For more info see: https://bitcointalk.org/index.php?topic=1218804

Absolutely. His payment processor is CoinPayments and this is a screenshot of the transaction screen, proving that CoinPayments indeed received the payment:
https://imgur.com/kH2t38u

This is the actual bitcoin transaction in question:
https://blockchain.info/tx/af1d2164d384dddab3ba407fc5aa15da9381b4487ea6afc9da9c339ef5de6237

Since EurGold did not dispatch any kind of receipt upon payment, and I'm getting no reply via email, I don't have any emails from the store itself.

Furthermore: he seems to have logged into his Bitcointalk account several times in the past 8 days, so it should be in his best interest to reply here and explain himself. Why would mr. Buckley avoid replying to my PMs and posting in these threads?

The online bullion store EurGold, run by mr. Shane Buckley, is a SCAM.

The short story is that I ordered some silver about 8 days ago and the owner is ignoring me and refusing to either ship or refund. I got ripped off for ~1.1 BTC.

See my post in the store's reputation thread for more info:
https://bitcointalk.org/index.php?topic=1141911.msg12754314#msg12754314

I urge mr. Buckley to give me my money back, or I will be forced to sell this debt to a collection agency in Ireland, which will be much less pleasant than settling this privately.

Just did that. Thanks for the tip.

THIS IS A SCAM.

I bought 20 silver eagles using bitcoin precisely 6 days ago, and I didn't get any kind of confirmation email. I thought that was strange, so I proceeded to email the shop several times in the above mentioned period. I didn't get any kind of response. In my last email, I asked him to either ship the product or refund me. No response at that point either.

The price did seem too good to be true (around $13.5 a piece), but I decided to take a chance anyway, which turned out to be a mistake.

DO NOT SEND YOUR BITCOINS TO THIS GUY.

THIS IS A SCAM.

I bought 20 silver eagles using bitcoin precisely 6 days ago, and I didn't get any kind of confirmation email. I thought that was strange, so I proceeded to email the shop several times in the above mentioned period. I didn't get any kind of response. In my last email, I asked him to either ship the product or refund me. No response at that point either.

The price did seem too good to be true (around $13.5 a piece), but I decided to take a chance anyway, which turned out to be a mistake.

DO NOT SEND YOUR BITCOINS TO THIS GUY.