Contract extended without my consent

Good day. i took out a contract with Vodacom in April 2018. The package was for a Huewei P20 Pro which came with a P Smart phone as a special for R699 x 24 months. Even though i was on a Top-Up deal, the bill was forever over R1200 every month. 24 months later when the contract is supposed to end, Vodacom tells me that the contract had been extended and will only end in august 2020 and that i should continue paying till then. Every time i call 135 i am always told different stories depending on who picks up. I called again on Friday 26th of June then i was told some new information that my contract had been extended by a further 24 months and would only end in 2022. I told them that i am just a domestic worker and could not afford to stay committed to their ******** contract because i do not even know what i am paying for, then they told me that i would only be paying R485 but this month i was billed over R900. I tried to request a statement and quotation for the contract but they refused to take my email address. When i called their cancellation de[department they told me that because i was in arrears for 4 months, they had extended my contract by the 4 months i was in arrears even though the arrears were settled in April already. An agent told me that it is their duty to make sure that clients do not exit or cancel their contracts.