UNHAPPY - CANNOT CANCEL MONTH TO MONTH SIM ONLY CONTRACT

So i took a Month to Month Data sim only contract in November 2021.. The sales agent told me its a sim only contract. So i will be able to cancel at anytime with 30day notice. I was working from home at the time and needed the data. However now that im back at work and have no use for this data. I called in to cancel this contract and to my SHOCKING revelation... I was told I could not cancel this contract as cellc has changed all these contracts to full 24 months and if i wanted to cancel i would need to settle the contract which will be about 2000. This is totally not on!!!! This is not what i signed up for but am now bounded to!!!! Can it not just be Cancelled and they don't give me the benefits as it was in the past sincing there is no device involved! im really livid with this! Where is the notification of contracts being changed to full 24 months? I did not recieve an sms or email or call about this!!! I am really disappointed in this service