What should I do if I'm charged for transferring stamps between my old and new passport in Thailand?

Today I went to Samui and got the 60 day extension. Most things were fine.

However, I had a new passport and had to transfer stamps from my old passport to my new passport. I was charged 500 baht for them to do so. This is wrong. The transfer is supposed to be free.

I told them it is supposed to be free but they said “no we charge a service fee here”. I told them fine, but can I get a receipt saying that I was charged extra for a “service fee”. They denied me this and kept asking me why i needed it. I didnt push it and eventually just said ok and left.

Just letting everyone know this can happen. Keep it in mind if you present a new passport and need stamps transferred.