I am leasing a vehicle and I have been late on payments. I am 1 1/2 months behind. I offerd to catch up the 1/2 month with a $200 payment then in 2 weeks make a full $400 payment to catch up till payment is due this month. The creditor refused and said they needed the $600+ toaday.

Yes they can refuse. They are not required to accept anything but full payment.

I am leasing a vehicle and I have been late on payments. I am 1 1/2 months behind. I offerd to catch up the 1/2 month with a $200 payment then in 2 weeks make a full $400 payment to catch up till payment is due this month. The creditor refused and said they needed the $600+ toaday.
[Comments on this post Myers3D agrees: Well, I guess that's life. I just don't understand how they can refuse a payment on a debt. If I were owed money I would accept whatever was offered knowing I would be getting something]

They don't want to extend the Statute or, in this case, void the terms of the contract which says X dollars on such and such a date; the bookkeeping would be a nightmare for them.