Poor service and lost of Tablet

bought tablets on the 17th of December. one was broken. took it back . the Manager Mr Leon then was very unhelpful. I said to you I am protected by CPA - apparently VODACOM have there own rules the don't obey to the CPA act they have there own "laws". up to today they did not phone me back once. Yesterday we phone again and was told there is a problem they don't have the tablet. can somebody assist please. I was told I am not allowed to stop the contract. there attitude and service is the worst I ever experience. please think twice befor enter into a Contract with VODACOM