False sales and misleading

I took out a contract with Telkom in 2019, and I was told the term is 24 months, I was supposed to finish this year August.. All of a sudden I am being told the contract is 36 months and when I asked for a recording where they told me that they don't get back to me, I have been requesting for callbacks but no one gets back to me. this is poor service and misleading and I demand that it be sorted out because now I am paying longer than what was agreed upon