Transmission which lead to a leaking radiator

I put my vehicle in the shop on 10-17-22 it had no leaks. It had been sitting for 3 months before I even put the car in the shop with NO LEAKS!! I picked the car up 10-31-22 paid $1,327.78 the mechanic specifically told me that everything was good to go and that they had done test drove it. It was already after 4 that evening and they close at 5. I left the shop and exactly 1 in a half hour later it’s leaking coolant smoking under the hood and giving me all these warning signs across my dash that I had never seen took the car back to the shop the very next day and they’re telling me it’s my radiator these people are so unprofessional because how are you just now seeing this leak that was never there before they screwed up my vehicle and I will be taking this company to small claims court!!