to submit a valid claim for a refund , a user must -lrb- a -rrb- submit the test issue in writing to duolingo within 24 hours after the test issue occurs , and respond to duolingo 's requests for information or cooperation , -lrb- b -rrb- not have directly or indirectly caused the test issue , and -lrb- c -rrb- have met all test requirements when taking the test prior to making a claim for a test issue .