fraudulant bill

I just received a phone call from WAm telling me that my husbandd opened an account in 2008 with T mobile, it was openeded in Idaho. The amount is 1,900.00 We have NEVER had an account with T mobile, we have never lived in Idaho, my husband was in Iraq duirng the time they say the account was opened. It is fraud, now they tell me they will send a fraud packet to my house I have until the 5th of Dec. before this is reproted on his credit report. How can I get this stopped long enough for me to receive the fraud packet, get the police report filed, etc. before it goes to the credit reproting companies? We are the victim and are being treated with rudely. Help