T Mobile Will not accept payment

I admit I have a past due bill with TMobile however when I called them to make payment arrangments I was told that they could not take a payment since the bill was forwarded to a collection agency.  However they were willing to take payment in full but in the same breath told me that the bill was due to the collection agency.  I asked for the name and number to the collection agency and was told that they did not have that information yet...What?? I had been a Tmobile customer for 5 years, the bill was forwarded to collections after one month and now I have no way to pay this bill, I have never, ever had a situation where I was unable to pay a bill that I owe. I literally cannot pay this bill because no one will take the payment.