I made payment arrangements

I made payment arrangements to pay back my private student before default. I received my final notice for my options. I called the final day that was November 29. I was told that was my last day. I said I can pay tomorrow when I get paid. The person had to get an ok because it was the last day. She said it was fine but I had to set up auto payments for like 13 month. I ask will that bring me current. She said after the 3rd payment. I was in a rate reduction program. .So I received the letter with my payment schedule. So November the 30 the first came out and I received a call in December because whoever skipped auto payment for December. But I made the payment after I was aware by their call. I don’t understand how you set up payment arrangements with me and send me to collections before my 3rd payment is due. I call them to them to give me the run around and tell me my payment is not enough. When those where the terms and conditions we agree upon to pay the amount. The collection agency is harrassing me with 2 options 15,000 settlement or 2500 then we can make payment arrangements. Have no answer from either how I am in collection when I have an agreement on a payment plan.