Mtn Contract complaint

On 27 April 2022 I received this message from Mtn: "Y'ello! Your contract term has ended. Your contract is changing from R173.04 to R 297.874 on a month-to-month term. All promos have expired." Therefore, I called MTN call centre 3 times asking for the cancelation of my expired contract, Mtn consultants kept me holding until the line went off after that I received this next message: "Dear Customer, your query *** has been closed. Please contact call center if you require more information. Thank you for using MTN. Have a Y'ello day." On 11 May 2022 I received this message: "Y'ello! Just a friendly reminder that your MTN debit order of R 350 will go off on 15-May-2022." I asked for a cancelation of an expired contract but they opted to increase my monthly premium. I am grossly disappointed by the manner in which Mtn is handling this matter.