Do not honor guarantee

I bought a maintenance free battery with a 24 month guarantee at Goldco on 22 March 2014. From November 2015 the battery started to give problems. I took it back on 6 Jan 2016 and collected it 11 Jan 2016.. Pravine(salesman) told me that they have to test the battery first before they can give a new one. When I phoned again they told me the battery had no water that's why it did not work. I told them it's a maintenance free battery that's why I never threw water in. They then told me it's not a maintenance free battery although they sold it as maintenance free at the time I bought it. There is two factory stickers on the battery, stating clearly that it is a maintenance free battery. They through water in and charged the battery, but when I came home it still didn't start the vehicle. I don't have the managers name, but the salesman in Pravine. Tel nr - ***