Basically where you went wrong was when you connected a to b, b to c, and c to a with a sensored motor. If it was sensorless you would have been fine. The hall effect sensor senses a magnetic field telling the esc where the rotor is then the esc powers up the correct phase. Which wasn't the correct phase because you had the motor wired wrong. When using a sensored motor you always connect a to a and so on. If it won't calibrate then reverse the channel in your radio and recalibrate the esc. The esc then knows what signal to look for to give forward power and which signal for brakes. I would try wiring up a different motor to the esc and calibrate the esc and see what happens. Without doing that I can't tell you exactly what's been fried whether it's the esc or the motor or both. Just that something has definitely been fried.