Americredit financial services inc Filed a 1099-C with IRS, now I'm trying to tell IRS I never worked for them, rip off Fort Worth Texas

There are many different types of 1099's issued.   A 1099-C is a "Cancellation of Debt" and has nothing to do with work performed for a company.

So having Americredit issue you a 1099-C that means that at one time you had (most likely) a Vehicle loan through them and became delinquent.  Most likely to the point where they Reposessed your vehicle.  This DOES not end your obligation to pay back the loan.   So if after they sold the car at auction you were still left with a balance, you are still responsible for the debt.

If you fail to pay it back one legal option they most likely have is to "Write Off" the debt.  However, with every Write Off, there has to be a corrosponding gain.  Where in effect you "gained" as unearned income the amount they wrote off.  As such you are responsible for the taxes on it.

Now, if  you are going to come here and say that you never had a car loan(or were a co-signer on a loan) that you were delinquent on and are 100% sure is not  you.  Then you have an Identity Theft issue going on and you need to attack this from that perspective.   

Also, you can look at least to one bright side to this.  If it is yours, the amount on the 1099 is the amount that is being reported, you only owe the taxes on that based on your tax bracket.  So for example if it was $10,000 and you are in the 10% tax bracket you only owe $1000.