Get in touch with the big three credit reporting agencies right now and dispute the charge. I am going round and round with a *&^$& wireless provider because they re upped my service for a year without me saying it was OK. Some lawyerese bull***t in the fine print saying they will automatically renew every year unless they hear from you.. whatever...

Anyway, a collector calls wanting about 200 bucks, and I tell them "aint gonna happen", then they say well, the last months bill wasn't paid, it's like 21 bucks" OK I'll pay that...
Get off the phone and then they call back saying " My manager and I have reviewed the account, and it will have to be paid in full"
Umm, you gonna get 21 bucks, or you get nothing..
we will need full payment..
good luck, you get zero, do not call my house again, and I am calling the reporting agencies and disputing this right now.
So now, when I get a threatining letter from a collection agent, goes right thru "shreadator" with the rest of the junk mail..

If and when you apply for credit, and they ask what the glitch is, tell them what happened and it really shouldn't be held against you. Be sure to contact the reporting agencies soon.
Experian is one, there are a couple others that I can't think of at the moment..