Pathetic service and breach of agreement by not rendering service as per agreement

I have Vox fibre at home, but during this period I have the service we have more technical issues and interrupted services than anything else. If it's not updates, then it service issues. When you call the consultant to attend to service related issues, he's hardly available, when you get hold of him and express your concerns, he becomes arrogant and demand to see a call record as to when he were called. I canceled my services with them due to endless issues and was advised that due to me not honoring my 12 month contract, I'm liable to pay a penalty!!! What happens to liability to VOX telecommunications for breach of their agreement in respect of service delivery. Certainly it's a two way. I am not going to pay and Cancelation fees to such an organization that failed me as a consumer.