Bad service

I took out a service plan with liquid capital. Last year some time. Unfortunately I had financial difficulties in December and Jan. They then canceled my policy on 21st February, but still went and debited my account on the 25th of February. I have not used there services at all. I understand that they canceled my policy. But why debit me after that still. I have tried contacting them several times, but I just get send from pillar to post.