[PSA] the "send it again and we will refund the first" message is always a scam
Number eight on the pattern list, and it has come up three times this month, so it gets its own post. The message says your payment did not arrive, or arrived short, or went to a deprecated address, and asks you to send again with a promise to refund the first. Sometimes it comes with a plausible screenshot.…
The chain is the arbiter and it is public. That is the entire point of it.
If your transaction has the confirmations the vendor's own checkout asked for, you have discharged your obligation and the rest is their reconciliation problem. Every version of this scam depends on you not checking, or on you feeling too awkward to say "I have checked and it confirmed at 14:22".
the awkwardness is the attack surface. people would rather send $90 again than have a slightly confrontational email exchange.
the genuine version of this problem is the wrong network, and that one is your fault and it is unrecoverable. which is precisely why the scam works — there is a real failure mode adjacent to it.
test with $5 first. every time, every new vendor. the fee is a rounding error against the downside.
and on some chains the $5 test costs more in gas than the discount you are chasing, at which point pay by card and stop optimising.
the crypto discount is real and so is losing chargeback rights. those are the two facts and people only ever quote the first.