Pathetic Service

I cannot believe that I even agreed to open an account with these people, fibre line installed 3 days later it stopped working. I reported it and nothing was ever done. It was a month to month contract so I did not renew it, now they come back 6 months later claiming I owe them thousands of money, I've requested the invoices which still 9 months later they cannot provide and apparently every month they are unable to provide this information I am being charged penalty fees and interest. Utter nonsense!!