Duolingo complaint: Invalid Test twice in One week

As per DET, During the exam, your response was determined to be pre-planned or found via an external source. This is not permitted. Your responses cannot be prepared in any way and must be in your own words to receive a certified result. My both test were not certified because of same reason.

I raised a question:
how can the response are pre-planned when we don’t kwon what questions we received in our exam and if my response were pre-planned that means i know what all question i will received in next exam then i will get 160 marks in DET.

If i used external source to answer the question then they need to proof the same as at the time of test i have not saw anywhere except keyboard and laptop screen.

Whenever i raise a question they are not providing any proof and every-time the response ‘read the terms and conditions’

I need to submit my score to the University for September 2023 intake