https://blockchain.info/tx/64fe199c663c9943cdf79b44f702ec5842969445aeb51d2376cf8e2d9ec534a5
133kp4hdg8Q49U5cUrzbZ3Ks6CxwUmrLa9 - (Spent) <-- This address is mine, does this mean it was a double spend? If so, how should I approach said member of this community? Would it be possible for an accidental double spend, or are double spends intentional and I'm getting scammed?
Thanks in advance!
You really haven't provided enough information to figure out what's going on.
What wallet are you using that has the 133kp4hdg8Q49U5cUrzbZ3Ks6CxwUmrLa9 address (Bitcoin-Qt, Electrum, MultiBit, https://blockchain.info/wallet, something else)?
Have you sent any bitcoins anywhere after receiving the bitcoins in transaction 64fe199c663c9943cdf79b44f702ec5842969445aeb51d2376cf8e2d9ec534a5 ?
I do not see any double-spend here. If so, the coins that were sent from 1SXG9wLG77uDWe7J2PynXgY4R1bB6Uqb4 would have gone elsewhere and would never show up at 133kp4hdg8Q49U5cUrzbZ3Ks6CxwUmrLa9 in the blockchain.
TLDR; I see no evidence of a "double spend". What wallet are you using?