Next time, put kinetic weapons on it. Might work better...
But seriously, did you make it a support ship? Do the enemy have techs that allow repair in battle? Do they have evasion techs? Is their battle speed better than yours, so are staying out of range? Don't assume that kinetic weapons are broken, when there are many other possibilities for the results you get, when you load a ship with a single type of weaponry, and short range, at that.