What kind of voucher is it? One of their practices that deserves bigtime complaints is applying voucher dollars ONLY to the "airfare" component of the fares, which in many cases is at or near zero anyway. They won't apply it to their own invented mandatory junk fees (like the "carrier interface charge") or to "optional" things like bag and seat costs. So the voucher becomes far-diminished in value to the point where I'd even call it a bait-and-switch (i.e. people think they're getting something far more valuable than it really is). Vouchers should count SAME-AS-CASH against another fare with no fine-print exclusions like that allowed.