Is $6,000 to fix exposed rebar and cracks in pool a fair price?

Having our pool replastered. After demo, the pool contractor told me that they found some exposed rebars and cracks around that. He said via voicemail that he has a solution for that but it will be around $6,000 to fix it. I feel like, it just need some cement to fill it up. I am not the original owner, we moved to this house in 2021. I feel like it’s their fault for exposing the rebar.