Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

I received $1000 and was asked to send it back. How was this scam meant to work?
Possible ways they could make money (or think they could): I would go back through your transaction history and see if it's disappeared.  Even with an assumed-rubbish interface finding a reversal of the transaction should be easy as you know the amount.  I wouldn't spend it for a very long time if it is still there, just in case my last bullet applies. Given what they knew about you (phone number and account details) I'd be wary enough to keep an eye on all my accounts, possibly wary enough to consider credit monitoring in case they try to open other accounts with your details.  Although of course plenty of people have legitimate reasons to have this information - if you've written a cheque the account details will be on it, and you might well be in the phone book or otherwise searchable.