Cartrack cancellation fee not paid all

My mom traded a polo vivo this year that i was the one paying for its Cartrack and the new polo we got was said it has a tracker already fitted to it so the salesman told me he’ll refund me the cancellation fee of Cartrack which he did but the money was not all of it. I tried calling him over 6 weeks till today he always tells me the manager is not there I went to the dealership they told he’s no longer working there and they don’t want to help I feel so disappointed because before you purchase the care they treat you nicely but after they’ve succeeded you to purchased you’re no longer important to them 😢