JustFly complaint: Customer service would not help change flights, left us stranded.

Booked flights to London flying back from Prague. Due to COVID we were not allowed to travel to Prague so needed to change return flight
Tried to call for help , on the phone to Just Fly for 2 hours then call got disconnected, tried again for another 2 hours finally an agent answered but was confused how to change a flight and even after asking what my contact number was , they hung up on me and never called me back, we tried again and sat on hold for another 2 hours before giving up . You can barely hear them as their call enter is so loud, they don’t seem to know how to do their job and they cost us hundreds of dollars having to pay for hotels as they left us stranded in London.
Do not use this company! They will not help you.
We also got charged over $500.00 to change flights which was out of our control.
Never use them again!