Discovery insurance wrongfully took my money and did not pay it back.

I am very disappointed with discovery insure. I ended my car insurance contract with them and moved over to a cheaper insurance. I had to take out the DQ tracker from my car. A person came a week after that and removed it. Last month they deducted over a thousand rand from my account. After my financial advisor contacted them it was a few days of back and forth where nobody had a clue what was going on. After a few days they finally said it is a penalty for not removing the tracker on time. According to them I still had the tracker in my car. I send all my call logs and sms message as proof that I confirmed with the guy who removed it. Could even send them a name and number of the person who did it. This was three weeks back. So discovery wrongfully took my money and now I hear nothing from them. What a disappointed from a company I thought would deliver good service. Looks like they only want your money and nothing else. I removed the dq tracker on time. The penalty was a fault on their part. I just want my money back.