looking for advice and I was dumb and bought a 24 inch 4 bulb fixture off eBay that was listed as new... we got it and it was definitely not new and the seller won’t respond... always one of the ballast doesn’t work so only one switch and 2 bulbs work... does anyone know what ballast I can use to replace it and is it an easy replacement job or would I be better off just caulking this up to a lesson learned and buy a different fixture