Originally Posted by ISTFlyer

TK and 99% of other airlines do not offer full refunds unless one of your flights are canceled.
If you need to cancel your flight at the moment, the fare rules would apply and you would receive your refund 2 months after the pandemic situation ends according to the Turkish Civil Aviation Directorate rules, however, if your ticket is a non-refundable promotional Business class ticket you have no luck of cancellation unless one of your flights are canceled.