Alltel ruined my credit

After being a customer for several years, I changed to Nextel. Alltel would not cancel my phone, I was not under contract. 3 months of calls, written and all of their bull I quit paying the bill, 3 months later (after not using the phone for almost 6 months)the billing stopped, but They have kept this alive on my credit report for over 10 years and just recently relisted it with another collection agency. If they only knew how much this $150.00 bill has cost them over the years!!! I have personally convinced dozens of people Alltel is not the phone company for them and I am sure they spread the story much wider(and wilder)