Sold 2 items 1 postage 1 collection to same buyer

Hi All

I'm not a regular seller and I had an item for sale with qty x2

i had a buyer buy both, 1st sale included postage but on the second item they selected pick up and messaged stating to reduce shipping costs they selected pick up.

ive just posted both items together (costing me more in shipping) I have never done a pick up before and found that it needs a QR code from the buyer.

i now feel like I’ve been scammed and they have either got a 2 for the price of 1 

has anyone been in this situation?