I called the EXP desk to book two separate flights in basic economy using two separate flight credits that were from flights originally booked in economy. The new flights were unrelated to the original flights (different dates and destinations). I was told that I was “unable to use the flight credits to book basic economy because the original flights had been booked in regular economy” (I don’t recall which fare bucket). It wasn’t going to break the bank (an extra $30/ticket), and each of the flight credits were for more than the cost of the new tickets, but nevertheless this seemed odd to me. Subsequently, I looked up the t&c for using flight credits and saw nothing about having to rebook in the same class as originally booked. Does anyone have any insight into this?