Vodacom,really,what happened?

My son had a cellphone contract with vodacom,unfortunately the phone was ******,but he kept on paying until the end of contract,which was end of May 2021.His debit order went of as usual on the 23rd of May,so it was suppose to be the last payment,according to Vodacom.He phoned Vodacom to cancell the contract on the 4th of June.So he is upset because he paid in May for the month of June,but they stopped his data and minutes.Then this month on 23 June,they took the money again for the contract that he cancelled on 4 June.We expext Vodacom to refund the R700 immediately and he would like the minutes and data that they cut of to also please be available again.How does Vodacom work,if you paid for something,you should get it,and if you cancell it,the money is not suppose to be taken again.If they want to phone him to rectify the situation,they can do so at 15h00,since he works underground and wont be available before then.His tel nr is ***-He is Tiaan Habig