Many thanks have posted away this morning

I have a default showing on my Equifax credit file for £37.00 but have never owed Vodafone any outstanding balance and have not had a contract with them for many years. Equifax say it's "settled" but I want the "Default" removed as it's affecting my score. Vodafone are unable to trace an account. Also my date of bith on the report is a year out of date. How can i get this done please?