How to get the negatives in the studio?

I didn't say yes beforehand. I left myself a trap. This is a bomb sold by all photo studios, and it is the last blow to customers.

I didn't say a word about it before signing the contract. After the customer paid the money and finished eating, the customer remembered it at this time. The studio opened its mouth to the lion. I want negatives 15 each -30 yuan. You coordinate with him. It would be nice to get it at a low price of fifteen yuan in the end.

It's better to give a photographer or designer a little 1000 yuan and get it all back.

It is difficult to defend rights.