Cell C MiAssist dishonest tactics

bout 3 weeks ago I got a call from Cell C MiAssist, who sold me their service, for R45 per month. I had to say "yes" to agree to the so called "terms"which included: 1.The service to be activated on my number, 2.The service cannot be deactivated with the first 3 month Subscription 3. The joining fee be added to my itemized billing When I got my sms with details to download the app and agree to the full legal terms of service, I read through the terms and was not happy to agree with the terms. Which means that I cannot use the app or service. These terms were much more in detail and very lengthy and took me about 15mins to read through properly. I then contacted them via email and asked to cancel the service as I did not want to agree to the terms specified on the platform before downloading the app. I then got a response from a Nonhlanhla that told me they will cancel the service but I will still be held liable for 3 months of subscription fee. This seem to me like underhanded tactics to get 3 months minimum subscription fee out of people not using their service. Why am I bound to the contract BEFORE actually accepting the terms of the service? Why am I held liable for a service that I cannot use, because I do not consent to the terms of usage?