how to cancel a contract with nymmg

I submitted my digitals to nymmg and an agent approached me. I thought I understood the fees and signed the agreement, but after reading reviews I realized it was a mistake.

I’ve already booked a shoot with one of their suggested photographers for $250 (after their original suggestions were $1500+), and I want to cancel the shoot and the contract. It hasn’t been executed on their side yet, so can I still cancel the shoot for a refund and not move forward?

Any advice is helpful but pls for the love of God, be kind!