Vespa — poor mileage of vespa scooter

I have purchased new vespa scooter an 29/11/2017 at ora motors g-1 atr towers, harbour park road pandurangapuram visakhapatnam.
Model:vxl-125cc engine no:m449m3159823. Already 3 company servises as per the schedules given in your vespa service book were done. Everytime i have reported at service company for poor mileage and low pickup of vehicle but the problem has not solved even after completion of 3 services. Since from purchase i have observed mileage but the vehicle is giving only 25km/litre. Hence i request you to give suitable instructions to your company people to solve the above problem.