I don't think most people here have read what I posted.
I said the payment was offered by a CC.
When we request a bank transfer we never hear again, so it cannot be the overpayment scam (though that scam is certainly clever!)
A bank transfer should be irrevocable. It is cleared funds when it arrives, although I do know first hand that banks can take money back out without the account holder being able to do anything about it; the case I saw was where the bank erroneously did the transfer (from us to a supplier in Taiwan) twice, and even though the supplier did not co-operate, his Taiwanese bank (acting on instructions from our UK bank where the error was made) just took the money back out of their account and sent it back to us.
But I am talking about CC payments. I still can't see how an overpayment can be made. The only possible benefit I can see is that the customer (who presumably is using a stolen CC, or intends to refute the transaction and thus force a chargeback) ends up with a load of our products.
The products in question are specialised industrial electronics. Very specialised indeed, and of no use whatever to most people.
I suppose some people like to collect stuff, in the hope of being able to offload it and get *some* money for it...
I am not a racist but Nigerian scams are common knowledge, and their economy is running at a level where they have very little use for advanced electronics which can be used only with very specific (expensive) western made factory automation products.
It is as if somebody ordered 25,000 locking wheel nuts for a 1975 Ford Escort.