unfair billing

we took out a contract for our daughter 5 years ago.she moved and has not used it.we landed up paying off on the contract.virgin active renewed the contract (without our consent) we have payed more than double the original amount and get harassed on a monthly basis.now told to settle the outstanding amount they can only give us 20%.sorry but thats a ******* as we have in total payed dubble to date.please help sort this out.