Not Impressed with services

So, I joined VOX mid of last year with the hopes that the internet connection and service would be outstanding. From June/July until end of December the internet connection was fantastic and uninterruptable (That was with three of us in the house using the internet). In the beginning of January (with just me living in the house) things started going down hill with services and internet reliability (I think VOX have bitten off more than they can chew). I emailed asking what is happening and they responded with a solution of "changing my IP address". 2 days later I notice the exact same issues, High Ping +1000ms, streaming Buffering, Live streaming buffering, sometimes the streams wont even load and it goes on. I think I sent over 10 complaints all coming back to me with the solution that doesn't even resolve the issue. If I could have I would have sent 50 complaints but it gets to a point where there is no use in complaining anymore. So I am now at a point where I am doing online course and the zoom meetings pictures get grainy and hard to read and it really affects the studies. Now it gets to the interesting part: I have asked for a cancellation after explaining how stressful it is to be with a company that doesn't know how to resolve an issue let alone tell me what the issue is for months. They still have the audacity to ask for there Installation Fee, the router collection, and want me to pay for a month extra notice with out giving a "****" about client satisfaction or trying to apologize from there side. So I asked if I can have my 4 months that I paid for internet back considering they couldn't uphold there end of the contract and adverti*****t with "fantastic internet", "Uninterruptable Internet", "excellent services". and there answer was "no that's not part of our services".