Telkom's deceptive advertising

I purchased a phone (HUAWEI nova 9) at Springs Mall Telkom in 2022. It was a 24-month contract that I saw in their catalog for that month. I was meant to finish my contract this year around August, but on Saturday, as I was walking by the store, I decided to go in and find out which month it was exactly. To my horror, I discovered that the contract had been changed to a 36-month contract, which means it will now expire next year. I feel so let down and so furious right now.