Honda 2 Wheelers India — about billing "scam"

Address:

GF, 1 To 5 Dev Residency, Opp. Keyur Park, Nr. Sukan Bunglows, Nikol - Naroda Rd, Nikol, Ahmedabad, Gujarat 382345, Ahmedabad, Gujarat

Yesterday, i put my bike at honda service center nikol.
today when i got bill i saw there is too much extra charge they included when i ask them why they charge like this they said me this is GST charge and you should have to pay but there was split bill first one about the material which they use during the service and second one is about the GST on all that material i asked about the separate bill then they said it's company process and it will produce by honda company . please let me know how's this will be possible