Customer service from hell.

Bad service there is a big room for improvement.I was insured with them for 1 year.Upon then serving me with a letter that my premiums are going to increase .I send them a cancellation letter on the 3rd of Oct.Despite this they still continue to debit my account on the 25th Oct and 25th Nov.Their retention Derpt phoned me on the 11th Oct but I made it clear ,I still want to cancel.I never had a single claim with them during my year stay with them.