PATHETIC SERVICE, FULL REFUND WANTED

Purchased a Canon printer online via Hifi Corp, been using the printer for personal use projects etc, during the month of August a new cartridge was loaded then the printer started acting faulty, took the printer to the nearest dealer, after a month of no feedback, followed up with the store they didnt even send the printer into Canon, only after enquiring the printer was then sent, no explanation around SLA's next steps or any detailed information mentioned by the store consultant whom she identified as being a new employee. the printer eventually got sent to Canon only then to be told that we were negligent as a page got stuck, please tell what is the purpose of a guarantee? I was not negligent as the same process was done previously when replacing the cartridge, I refuse to pay for courier fees I want my refund as I have paid for this machine and not liable for any faults. Hifi corp does not have any customer service and I will not support them going forward as they are trying to do good people in for the hard earned money!!! Pathetic service and now they will be keeping my machine that I have paid for and no headsup given on their process, I DEMAND MY FULL REFUND WITH IMMEDIATE EFFECT!!!