Gift vouchers for TIF's are usually sold as an hour of flight time rather than a dollar value. If they don't expire and some chap waits 5 years to use it, it will likely cost to company more than what was paid to make the flight.
Given they have waited so long to use it there is not a high likelihood they will return for further training anyway.
In the instance that started this thread we wouldn't enforce the expiration date that strictly.
this is a prime opportunity for any flying school in the same area to offer to honour the certificate and at least partially redeem the industry.
Flying-spike where do you work?? I want to come get $300 worth for free if that's how you operate.