Ethical issues aside, as my question is purly theoretical, as a search revealed nothing.

I booked a T fare for a quick flight to Florida several months ago. After my initial purchase, I decided to pay the difference to upgrade my ticket to FC (A Fare).

If I were to cancel my entire trip, would I receive a refund of my ENITRE fare (ie. the cost of the T fare PLUS the difference I made up to make it an A Fare), or would I be forced to "eat" the portion of my A fare that was originally booked as a nonrefundible ticket.

Thanks