Brief question on mission

Hi,

I am gradually getting to grips with Iwar 2 EOC but theres this mission where I need to find a naval base and take out a ship that has clothes for the stepsons. Anyway this clothes ship has 2 massive ships surrounding it and I just cant take them out, my weapons arent even touching them!

I was wandering what people would suggest my best course of action? I am using quad PBCs and a rapid fire PBC, assault loadout. Any ideas how I can do this? Im not 100% sure Im even at the correct place, I mean how do I know which bases are navy bases? In regards to this specific mission well the place I am trying is flashing red on the galactic map before I get there and right enough when I arrive the find navy base objective updates and there is a weapons carrier. Is there anywhere else I can find weapons carriers its just I dont know how I can get these weapons out of the place as when I attack the transport the two giagantic escort vessels attack and they have like these massive cannons and my weapons, missles(Seekers) dont seem to do any damage.

Any help is much needed and appreciated