OK, how about this. Last week I flew PHL-MIA on US, MIA-IAD on UA, and intended to fly IAD-PHL, all on non-refundable one-way tickets, but due to weather the last flight cancelled. The later UA flight was already overbooked by 10 due to a prior cancel, so I just refunded that leg (allowed due to the cancel) and rented a car back. And promptly sat in traffic for almost 4 hours.
Should I attempt mileage credit, even though I refunded the last segment? My thinking is it won't work, and it being 500 preferred miles I won't lose sleep over it, but I thought I'd ask ...