Bike Claim - Insurer is approving only for repair?

I have comprehensive insurance to my bike. My bike met with an accident and it had damaged fuel tank of my bike. The damage to the fuel tank is minimal , but company authorised repairer is saying –“ They will not repair the bike fuel tank but they will replace it only.” Because it’s company policy that they won’t repair parts, they replace it only. On the other hand the insurer is saying that, “They will not pay for replacement of the fuel tank because damage is minimum”. And asking me to get the fuel tank repaired from local mechanic and submit bills for claim. If I get the fuel tank repaired from out side the authorised service station, then I will not get the original holograms of fuel tank from bike company. I want to keep all parts original. What to do in this case?

Insurer company is right that it will only pay for repair. Because insurance is to bring the insured item back in the same position as it is before the claim.