Why does their service suck

SO, after waiting 8 weeks for Fibre I cancelled it. The the **** started. Invoices with weird line items... Money taken out of my account with no clear consistent reason or amount... First it was 900... then 896.... but they sent invoice for 850 and took 850... then cant see on their system why... then insures me that they will credit with next debit order... which doesn't happen. Then is unsure why they did it and realizes that it must have been "hardware costs". Then, suddenly there is a process through which i now need to spend money to get the Hardware back to them. Which I do and they promptly take their pound of flesh for. Then I get informed that my money will be credited on next debit run!!!!! AS IF. So I ask for cash... which after some confusion will be deposited into my account within 48 hours.... which was 48 HOURS ago. So then I phone Accounts and get told that the refund was only authorized yesterday and would be paid somewhere in the future since the supervisor is not at work... Wow, just wow... what happened to the amazing service I have had for over 5 years... please can I see that again...