Help! T-Mobile and Debt Collector trying to ruin my credit!

I'll try to be as short as possible,
I relocated to Orlando in Dec., And started an account with T-mobile, after two months I relocated to live with my parents (in the countryside)
In this area I received no service from T-mobile, after contacting T-mobile they informed me that under their contract I could cancel and avoid the late Termination Fee ( because they don't have any toweres where I live). It took me a few weeks to get my drivers liscene changed and get settled in and then fax my drivers liscence to T-mobile from the post office. They snail mailed me back saying the fax was unlegible. I sent another one and they snail mailed again saying that it would be sent to the proper dept. to be validated. this process had taken a few months a lot because of the fact I was re-locating and dealing with a pregnant wife which was adjusting to life in America (she's Ukrainian).
In the middle of may I received a statement from T-mobile (they had not removed the Termination fee) and was told that I had till 6/14/07 to pay it. a Couple days later 5/23/07 I recieved a letter from T-mobile's creditor stateing that the claim had been transfered to them before T-mobile fixed the balance.
The debt collectors informed me I had less than 2 weeks to pay the debt or they would put this against my credit and that would make it difficult to "buy a house, get a loan, a car, credit cards etc." Which was followed up by a very rude call from the collection co. stateing the same. I told them I had not received a break down of the balance from T-mobile so I don't know what is valid and what was not, they said that wasn't their problem and that I could contact T-mobile but it didn't matter anyway by the time I got things straightened out I'd be out of time and my credit already would be in bad standing.
So I faxed them a reply stateing that the Full amount wasn't correct and that I owed about $75. of $372
I later recieved a letter stateing that they received my fax and were validating it (this was roughly around June 1st) I had not heard from them till about 4 days ago. They called agian and said that I had to pay the full amount by the 1st or they would ruin my credit making it difficult for me to get loans, mortgages, cars, credit cards and a job ( that was their words) I told them the claim wasn't valid they said they called T-mobile and T-mobile said that the whole claim was valid.
I spent the next night on the phone (on hold of course) for over an hr. I was transfered to about 3 different people in 3 different dept. the last being the Financial dept. and they all said the same thing.
1. They couldn't give me a break down of the balance because the balance had been sent to the creditor and T-mobile no longer has access to it. (they said they could pull up the general info but not the detailed info of the account)
And secondly they told me They couldn't contact the Creditors to tell them that this was not a correct balance, I even asked who they could contact to do this a Manager. director, Human Resources Public relations whoever, they told me they had no one that they could contact which could contact the creditors about this situation.

so my Delima is Saturday my credit which I've been building only since Dec. it's getting ready to be totally leveled! And I'm not sure what to do to stop this for happening or how to back track this after it does happen.

I also contacted the creditors they were willing to give me somewhat of a discount but there was still a portion of the termination fee left and there is still unknown things that they want me to pay for. The told me that "T-mobile did all that they would do and that they (the creditors) validated that the claim was good through T-mobile and they weren't going to do any thing more."

I then asked if I could have more time to pay off the amount they wanted because they only gave me 1 weeks notice they said no! and that if it wasn't paid in FULL or the FULL with the discount they'd screw my credit.

My 1st question is their something I can do to stop them in thier tracks before Saturday for example another Fax stateing that I'm still disputing and for the reasons why I am.

Besides this I'm clueless what to do and where to go from here, any advice would be GREATLY appreciated!
Distressed peon fighting against the Mogules! :shock: