Check for Chain slackness.
The chain should have around 25 to 35 mm slack on its lower side.This happened to me once,the chain was over tightened[just 10mm slack]
Riding the bike felt like riding a bloody underpowered moped. And it got maxxed out at 98km/h. No matter for how long i held the throttle full open, the bike just wouldn't cross 100km/h. Earlier i had touched 122km/h on the same bike. Mine is a 2008 P180 UGIII.
The 2009 p180 is capable of a bit more and i guess the guys who sold it to you didn't do a thorough PDI. Get it checked from the service centre. If they act smart, go to a local mechanic and ask him to diagnose and then go back to service centre and tell them what exactly the problem is.