This may help
I also went to the Quboz Q&A section and the page link to cancel comes up with an ERROR 404 notice. Funny that. What I could gather is that the billing will continue until the end of the month despite canceling it now, which is strange as under the Q&A section, it states that once you cancel on your end it will take 48 hrs to finalize.
Good luck on getting it done.
All the best,
Nonoise