ACT Fibernet — Worst connect worst customer service and cheating approach

I had installed their broadband with a six month pack and in a week I started getting the slowest connection possible. Their engineers kept passing the buck to due to G20 their wires were cut but despite continuing slow connectivity I got fed up and asked for cancellation and a refund. Their customer services kept trying to convince me but being adamant I just asked them to refund and then their agent said that there is no refund and when I escalated the matter there has been no response and they have blocked me on Twitter and all social media. Their CEO and senior management forget replying are not even acknowledging my mails.
They are forcing me to continue with their extra super slow connectivity to avoid refunding my money
Is this the way to ensure customers don’t leave and will have to now look for a legal remedy