I've dealt with the Melbourne shop for over 10 years and have always found their service to be excellent.

I just had to return a Quell carbon monoxide alarm to the Melbourne store. I couldn't believe such an important safety device could be faulty but I tested it on three CO-producing devices (metho stove, home gas heater, and car exhaust) and only got zero readings. The guys at the story couldn't believe it either, and embarrassingly I had lost my receipt, but they found the transaction history and took it back anyway. They even called a week later to say the Quell company had tested the unit and it WAS faulty. Unbelievable. But yes, the service at Whitworths was really great.