Why do you think it is a scam?
You offer Click and Collect on your listings and C&C items are often sent to branches of Argos.
The buyer may be in the UK or somebody else is collecting their parcel for them.
Make sure you send it to the address in the order details. There should be a code beginning 'eCP' as part of the address.
Make sure you include the code and use a tracked service.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)