Item not received

I bought an item and today received a bag with a bit of paper in it saying that because I didn't pay for fast delivery they have send this note to say it will take longer.the tracking now states delivered but I haven't received the item I paid for is this a scam .I've been on Ebay for a number of years and never came across this .please if anyone can help 

You need to start a return on here:
https://www.ebay.co.uk/help/buying/returns-refunds/return-item-refund?id=4041
select "Item doesn't match description" and if necessary escalate it to eBay after 3 complete working days.