Royal Enfield - Manufacturing Defect of Royal Enfield Supermeteor 650

The chain tightening of the motor cycle is not possible as the wheel is fixed at the rearmost location of the adjustment slide of the rear wheel in the new motorcycle. The chain is hitting the chassis as it is too long and loose. Initially, I was not able to figure out the problem as the bike model was new for me. The service Centre is telling that it is a design problem and the customer support is telling that they have referred the matter to the service department. My vehicle has run only **** Km. The sound started becoming unbearable just after the vehicle has run **** plus Km. The service Centre is saying that they will replace the chain under warranty. But next time also when the chain stretches, I need to change the chain again as the original equipment chain is longer than required and the wheel will be fixed at the rear most portion of the slide. Both service and support department is playing and not resolving the real issue. Super meteor *** is a new model of Royal Enfield. The company owned service Centre team themselves were groping in dark to find out the real issue. My vehicle is in the company service center for the last more than a week.
No resolution is in sight.