Netstar turnaround times a joke

My 80 year old father cancelled his Netstar contract in June 2018 when he sold his car. Netstar continued to deduct premiums for some "value added service" he had taken out years ago. They never told him when he cancelled the tracking unit that he had to cancel this service separately. Surely when you cancel one contact it cancels all services attached to it. Not with Netstar. After waiting for a reply from 25th August 2019 (Automated response say's you get a response within 2 days.) to cancel the contract and get a refund finally they call today (Only because I threaten to take them to Hellopeter) to say they will cancel the contract but no refund of the 14 months of premiums. The premium might not be much to them but to a pensioner it is.