Unhappy customer

I had insurance with nedbank and wanted to add another vehicle on the policy. I phoned them in December before collecting the car at the dealership but they were not able to assist. I covered the car with another insurance company for January. I phoned nedbank insurance on the 2nd of January requested to add the vehicle under my policy effective 01 February 2024. To my surprise, they deducted premium for January also. I phoned them to notify them that I requested the cover to start on 1st February. I even send them proof that I had cover for January. After investigating, they told me that they deducted premium for January because I didn't say I've got cover when I phoned in even though they could confirm that I requested cover effective 01 February and the issue is closed . Basically I paid double premium for the car and nedbank insurance doesn't even care. I didn't authorize the January payment, but they did it anyway. What a bad experience at the beginning of the year.