Crude Oil Board

All,
I have a question on a situation i am in and need your feedback.
Oil company was suppose to deliver for example let’s say 150 gallons of oil but they delivered 350 to fill the tank. Now they are saying I have to pay for the full amount of 350 gallons. I am in the State on NY in LI what can I do? My plan was to get more oil later at a lower cost (if that happens) in the future. So later I can get 200 gallons at the cost i want (possibly lower) not at the cost they just delivered.

They said they can push off payment on the remaining 200 gallons for 5 months.
The oil company is not allowed to take oil out of the tank. What are my options? They want me to pay the entire amount in installment at the current price, which I did not sign up for. What can i do legally/say for the remaining 200 gallons which I did not sign up for? They said they would send it to collections if I did not pay or accept a payment method. Can they make you pay for the entire amount?

I suggested that i would pay for the 150 gallons i ordered. The price should be adjusted to a future market price as I choose from now to next 5 months for the remaining 200 gallons.
Thanks for your help and feedback.