Discovery insurance causing me a depression

Hellow Peter,

I dont know where there you can help me. I canceled my policy with discovery car insurance last year around July or August 2020. So this year i made a claim with my current insurer the claim was successful later they asked me about discovery insurance i told them that my policy with them was cancelled last year. So now am struglling to get cancilation letter from them they told me that there is a sustem error they are struggling to cancel it on the other hand my claim cant be processed without cancelation letter . Dont know what to do any more when they say its a system error.

Regerds, Yandisa Siyotula