Mileater medals work in arrears. Once upon a time when Father Christmas (who was on reception at PBP) was the org, they where sent out before about March. However, under the new org whom I don't believe exists in the flesh as he's never been sighted, it takes longer and longer to receive medals. I reckon shortly the medals, if you want one will pass your diary submission for the current year.
Also, there isn't a medal for 300,000 miles!!!!!