I've received an email from App Store Purchases. Headed 30nov_ereceipts.docx.
It's an invoice type thing saying it's paid by credit card.
For sports keepfit equipment that I need like a hole in the head. You would understand if you saw me!
At the bottom of the page it says if you didn't purchase this click here.
Should I do that or is that also part of the scam?
Don't click on the link. At the very least it will tell the scammers that their email has found its way through to a valid email address, meaning that they can then be confident that the next few thousand emails they'll address to you will also reach you. (i.e. you could find your inbox flooded with spam and scams).
Do not click on it. I do not even think Apple sell anything else but technology, but if they did I doubt very much that you would find that phrase n any genuine invoice.