Struggling to cancel cover since 2020

I have been trying since April 2020 to cancel insurance with Virseker as I do not own the vehicle that I requested insurance for. I cancelled via email and never received a notification that I should cancel in a different way

I was retreched in 2020 and can no longer afford a vehicle

They are now saying I was meant to phone after following up numerous times

I need to claim back my premiums since April 2020