I'm fuming n very disappointed

Im not happy at with the way Mtn conduct there Contracts I don't if they don't understand the meaning of 24 months contract or they just feel like they can do whatever they want with my money. I had a contract from 2020 to 2022 July That was the agreement between us, But boom Mtn is debting from my account I'M NOT HAPPY WITH THE SERVICE IM GETTING AT ALL NOW. I CALLED ON THE 1ST AND I WAS PUT ON HOLD BUT THE STAFF MEMBER THST WAS HELPING ME JUST PUT ME ON HOLD ONLY TO SPEAK ABOUT CROPTOPS AND THEY WERE BUSY LAUNGING AND THEY HANGED UP.