Being charged for services that I have not been using

Last year around October Vodacom has Sales Agents going door to door informing us about the Fiber they are going to launch in our area. The sales agent told us that Vodacom will only start charging R599 once the Wi-Fi has been installed, and that we will receive an sms that is going to notify me. Around December if I'm not mistaken they sent us a router which had to be installed by a technician. Another sales agent came saying that we were supposed to sign for a Dingle that would give us LTE for a month before the Fibre is connected...... This year around March/April I received an invoice stating that I owe them around R3000, but we only started using the Fibre in March...... Today one of your call center agents that deal with accounts tell me that the contract starts being active the day I sign for it. No one told me that, and I don't understand why I have to pay for something that I only started using this year... This is unfair as you sent agents to our homes who were not well informed about the Terms and Conditions, because I listened to what they said thinking they know everything. I have been telling the call center agents why I refuse to pay that amount because it does not make sense to me. Why am I being charged from October, whereas the Fibre only started being active in March. This is unfair I really am not happy with this