[Resolved]  Bajaj Pulsar 150 — bad sevice,excessive improper billing

i have a pulsar150cc (old model) bike that i had given for complete engine overhauling at krishna motors vishrantwadi (an authorized service outlet of bajaj sai service) pune where i got very ill service and bad response unlike unlike other bajaj service centres.
the engine was poorly overhauled n hoarse noises were still coming from.i checked for it at other services for n i was reported for infurious parts fitted in my bike.in the the same course i showed them the bill given to me by krishna motors and i was surprised to see that i was stupendously over charged and also i was given improper bill with no invoice no. n all.i again complaint to krishna motors to give proper bill n my exact refund but they refused.i was charged rs11284 which should be nearly rs8000 according to other service centres.the difference is near about 3000.i have confirmed their billing at several other authorized service centres too but even that they are not ready to accept their guilt.
plz guide n help me out...