Miles….and miles

So we have a few exits closed due to construction . In order to go south from our one Walmart and Sam’s one has to travel north a mile to the next open exit then south past the closed exit. On the offer card it shows milage if the exits were open but during navigation the true detour milage shows up. In case this affects anyone else in any market, there is my PSA.
I’ve skipped a few of those offers …esp during rush hours etc.