Poor Customer Service

I had fibre installed and it worked a few days and then it said connected without internet.I called them numerous times and all they did was asked me to read the Mac address and IP address.it still wouldn't work,they then told me that they would send someone out to have a look.its been 2 months and nobody came.I sent them an email to cancel subscription and then they sent me a bill dor R1725 that needs to be paid.I don't understand how I must pay so much when I never had the benefit of using the fibre. The customer service ia very poor and up until today nobody contacted me.ai switched off the router as they disconnected my service and I packed it in the box it came. Please advise on what I can do?