Disgusting service from cell c they cannit solve a small issue

On 04/03/23 i sent back a laptop package which i had cancelled due to that the lady who opened up an application informed me after the application was done in February that there was no stock of the laptop i needed. I then cancelled straight away and took up a cheaper contract same model with MTN it arrived on the 04/03/23 the exact same day i had returned via RAM couriers and phoned cellc to cancel the contract the lady confirmed it was cancelled on the 06/04/2023 i received a statement of R509. 47 to be debited by the 18/04/2023.i then started calling the cellc Customer services and kept logging the query with different people i spoke to everyday non stop to try and cancel this contract Alkani, Thembi, Ayanda, Naledi, and today Lebogang Rangwako, yesterday was the 18/04/23 they debited my account for R509. 47 for something i do not have i called frustrated and the lady could of course not assist me as i was told that ot takes 7 days for them to refund. That was money which was allocated for something else. Are they going to pay back with interest? When will they refund me How when nobody from cell c can answer these questions. I was told a manager from the company will give me a call.