Vodacom refuses to cancel contract after it ends

Hi, Vodacom is refusing to cancel my cellphone contracts after numerous calls. My first contract finished in September 2024 and the second February 2025. They are refusing to cancel and are sending me from pillar to post. I am a pensioner and I've explained this to them that I need to cancel and don't want to renew my contract. I need to cancel these contracts as the money is needed to help with my medical bills, I am frustrated and the call centre agents are very dismissive and rude to me.