A Picture is worth a thousand words. So here are some pics. Someone with a Like 150i could post some as well.
I looked for a Like 150i parts diagram online, and found one old one where they used a mechanical hub/cable piece like the chinese scooters use. the mechanical unit sits in line with the wheel and is turned by the wheel. I am assuming it is not one of those. If it is, I could see that if the piece inside the wheel hub that engages the mechanical arm stripped out somehow...that it could take a wheel replacement.
More likely, though, is that it is a sensor/ring system like the DT300i. And in that case, the sensor (see pic) bolts onto the fork at a precise location (because the rotor/hub is also at a precise location), and is not adjustable in the same way that the rotor is not adjustable. It bolts on . Period. There is a small gap between it and a fixed magnet attached to the wheel (see pic). Somewhere in or among that ring is a magnet. It works just like $12 bicycle speedometers. As the moving magnet passes the fixed sensor, the computer keeps count and multiplies it times the wheel circumference to compute distance and speed. Here is what the sensor looks like on the DT. Notice the gap to the sensor ring. Notice that it is bolt on and not adjustable. What did the OP's dealer do, exactiy? The sensor itself can be replaced in less than 10 minutes by someone who has never seen it before. The wheel should never need be removed. What did the dealer do? I cant cast aspersions because I dont have the bike in front of me....