IMO, you didn't get what you paid for, either by mistake, or on purpose. I've only built one trike, with a 500w motor, and on 14s lipo with my 270lbs on it, it would do over 40kph. About the same as the same motor kit would do on a regular bicycle. So unless those little rear wheels are producing a lot of drag, a 1000w motor rated for 55kph @ 48V on your trike should do close to 50kph on 12s lipo, and should do close to 60kph with the wheel off the ground. After reading everything here, I'm convinced you got a 350rpm motor @48V. Wether it's a 1000W or 500W is to be determined. It also appears they substituted a 500W controller for a 1000W controller, which makes me think they sold you a 500W motor as they usually come with a 500W controller. Motor and controller wattages are continuous operation ratings, not peak output ratings. A 500W 30A controller @50V is 1500W, 2500W at 50A, etc. It's still possible you have a speed limited controller, but to determine that, you'd need to open it up and check the internal wiring or try another 48V controller. If you were in the US, I've got a new 48V controller I've never used you could have, but shipping to AU is prohibited by cost. Another possibility is that the phase and hall wires aren't correct, though this usually makes for a rough spinning motor.