I bought a new battery for my 1999 Xsara VTR from Halfords today but I can't seem to fit it to the car. On the existing battery there are plastic tops that screw on to the battery positive and negative feeds but on the new battery there are no grooves for the plastic tops to screw on to. Have I got the wrong battery and if so, how do I go about getting the right one? The one I bought is the one that Halfords recommended to me.....