Does the blade not spin at all? Do the headlights and self-propel work? If so then it sounds like a safety mechanism. Make sure the handle is fully extended and locked, and press and hold the safety key before and while pulling the blade bar in.
If the blade spins up on a driveway does it shut off when trying to cutting grass? If so raise the cutting height and sharpen the blade.
If none of that helps, try calling Ego in the morning on a weekday when call volume is lower than peak evening and weekend times.