FlyerTalk Evangelist
Join Date: Nov 2018
Location: Istanbul, Turkey
Programs: TK Elite Plus,BAEC GGL,ITA Executive, AFKL Gold,QR Gold,HH Diamond,Bonvoy Gold,ALL Gold
Posts: 14,186
Qatar Airways is not responsible for the changes of entry/transit requirements.
This is not Qatar Airways' decision and they must adhere what the government tells them to do so. In this case the State of Qatar has implemented a COVID test rule, not Qatar Airways.
There was another passenger who was affected by Pakistan changing their COVID test requirement from 96 hours to 72 hours between he was at check-in at the gate and he was at the same situation.
I'm sorry but it looks like your only way to fly would be to lose your upgrade, pay the no-show fee. Although, it's sad but it's the truth that your fiancée should have checked the entry/transit requirements for your itinerary regularly and comply with them.