Supersonic after sales service is non-existant

I joined Supersonic many years ago because it was easy to get through to their call center - I have been on the line on numerous occasions and given up after 25 minutes of holding. I have sent through 2 requests to cancel my subscription as I am relocating and the reply was that an agent would contact me - I have never had a phone call. I have given ample notice but now I don't know where I stand