Hey that sucks on the twat trying to scam you.
As pete says the chances of two packages not showing up are nil or **** all.
Apart from the delightful thought of you turning up at his door and doing reps with his head another option might be your postage receipt.
If its the same as Ireland , the receipt has the bar code. So even if it wasn't recorded you could run that and it usually says completed or not .
It's got me out of bother once or twice
Buyer: eh nothing on my end
Me : (chancing my arm a bit) it says here completed . Which means delivered it think?
Buyer: (on a Sunday) it arrived today.
Me: cool never knew royal mail delivered on Sundays
If you do go around , wear a headcam I wanna see his face .