hi all long story short car wouldnt start on sunday bumped it and it went but battery light on so took to halfords bloke comes out with his tester and says the battery on car is gone its only showing 11v and 80amps instead of 12v 480amp . so changed battery car started no problems went on a long test drive every think ok today wife goes work on way to pick me up battery light on dash on again battery flat . have halfords done me ? could i take battery back was 96 pound but they have my battery they may have scrapped it . what to do ?