Sprint PCS Sprint Cellular Failure to follow Their own policy Overland Park Kansas

I live in New York State and had been a Sprint customer for 15 years. When we had to move to a different part of the state, we found out that we were moving into a remote area with no sprint coverage.  We contacted sprint and asked them what the policy was  when this happened. They asked us for our new address and verified that we were in fact moving to a non coverage area so we could get out of our contract with no fees.

They sent us an email with instructions to follow. This required us to send information via email to prove our new address, etc.  When we did that, the email came back saying the email address was not valid.  I called Sprint and explained the situation and they told me to go to a corporate Sprint store to provide the proof and to return the phones.

The nearest corporate store was 20 miles away so I drove there, turned in the phones, and provided them with the proof of new address.  They gave me a receipt and I was on my way. The next month, I received a bill from sprint saying that I owed $468 for an early termination fee and for not returning the two cell phones.

I called them up and spoke with an agent. She said she saw the notes on my account and that I should disregard the bill, the problem was that the phones hadn't been "checked" into the warehouse and that once they were inventoried the bill owuld be reversed.  The following month I got another bill with a late charge attached.  I called them up again and re-explained the entire scenario.  This time, the agent said there were no notes on my account and they have no record of me returning the phones.

I asked to speak to a manager.  35 minutes later, a supposed supervisor came on the phone and we went through the entire scenario all over again.  She told me that there were no records of anything in the system. I asked her what I had to do and she said I needed to take it up with their dispute resolution department.

She tried to transfer me over their, but lo and behold the call was disconnected.  A coouple of days later, after calming down, I called back and asked to be put in touch with dispute resolution. They transfered me over and I ended up in an endless loop on hold. I waited a good 30 minutes and no one ever picked up so I hung up.

I tried again later that day and I finally got through to someone. They told me again that there were no records of this dispute in the system and that I had to pay the $468 (they waived the late fee).  I explained that I no longer had the phones and that I had turned them into the corporate store two and a half months ago.

They told me to mail copies of everything and that they would investigate.  Here we are almost a year later and now my account is in collections with Diversified Adjustments. They want nothing to do with any explanation of anything and now my credit has taken a hit. I firmly believe Sprint is acting in bad faith in this situation and I don't have any clue what to do. It is almost as if they harass you and obstruct you until you break down and settle the money. I followed their procedures and they refused to abide by the agreement. I will never be a Sprint customer ever again, even if they were the last cell phone company on earth, they will never have me as a customer again.

Does anyone have a suggestion on how to resolve this?  Do I just pay the $468 and be done with it?