CANNOT CANCEL POLICY WITH LIQUID CAPITAL

I took out additional service plan cover with Kia Liquid Capital for my Kia Sportage. I have sold the Kia and is trying to cancel the cover without any success. You cannot get hold of them telephonically nor do they answer their emails. I have send numerous and it has been read because I receive the notifications when the emails are opened but no response what so ever. This people have no idea of what customer service is. Stay away from them and take up other options if you want extra cover because their customer service sucks.