Mahidra Two Wheelers — vibration problem beetween 46 to 60 speed

I Purchased an Mahindra Centur on 28 November 2015 form your authorised dealer Ramdevji Tractor City Botad State Gujarat. My bike is Vibrating at speed between 46 to 60. On first service I complained this problem to Same dealer. Dealership reply me a Foolish Answer that due to the fuel economy system that problem is occur either rise the lever or decrease the lever from that speed. After that on 2nd Service I complained Same Problem. At that time Same dealership reply that it is normal problem that occurs in all models of Centuro. After that I Complain on 22 May 2015 in your Mahindra Customer care no. [protected]. They reply me that we call you in 24 hours. By till now a day Not a single call is coming from your company. Your service enginner Mr. Satish Gajjar is Coming at Same Dealership on 30 May 2015. He Replayed that Parts are to be Ordered which is Coming after 7 Days. put your bike in this Dealership Workshop. At 11 June you will revive your bike. But till date no work is done in my Bike. So kindly do need full help. Awaiting for you Positive Reply.