Geeyem Motors — Service center does not provide replacement for damaged parts.

I have given my vespa elegant for service few days back. My vehicles fual guage is not working. When I ask with the service center they said like some part is damaged and they don't have the replacement for the same in stock. They are not having the part for the last three service. If they don't provide replacement for the damaged parts where should I get it. This is the first and last time I'm going to escalate this issue. If they are going to repeat it I will raise this issue to consumer court.