Paying Vodacom for internet access i dont get

I had an upgrade done on my contract, i now have 400GB Home Internet Price Plan-Top Up Line Rental for R1,129.56 (due to black Friday special i pay R799) and since then my internet speed has been less than 3mb/s I have reported this problem on numerous occasions, i have had to take my modem for testing, had to have my sim card tested, had to do so many things but still nothing. My phone that is on a top up contract for R258 get 24mb/s in the same location whiles my new contract gets less than 3mb/s. Are they trolling my account so i can not actually even come close to using the 400GB per month???

I work from home and need internet access, im paying R799 for a service i am not getting. Vodacom shop has informed me that it it a network problem and the network department says nothing is wrong.

I wanted to cancel this contract and was told i need to buy myself out of the contract by paying for the entire thing up front.

I am tired of paying for a service i dont get, no one is helping anymore because their is “nothing than can be done” How can i get out of this contract???