Originally Posted by
3Cforme
A and P fares are typically the types of which aubreyfromwheaton speaks. They have a coach fare basis with instant (as available) upgrade to F. An employee poster has talked about IROPS compensation when an F re-route isn't available. It's unlikely the OP would have wanted to wait for available F given the time sensitivity expressed up-thread.
There is compensation for these UP fares and it's more than what's been mentioned above. Look at your fare basis code, if it has UP anywhere it is one of these fares. Either way you're due a partial refund or a voucher, contact Delta on delta.com