Fluorescent Light Problems

I moved into an apartment with a single 15" fluorescent light bulb that I thought was out so I ordered one off eBay for 5.00 and I put it in along with a new warmer and the bulb got very bright and blew as soon as I flipped the switch, so now I am thinking bad bulb so I go to the hardware store and buy another and put it in the same thing it blew. I take the fixture down and find that the inside was burned at the ballast and the wires melted. I replaced the ballast and bought yet another bulb and this time when I turn the light on just the ends of the bulbs have a slight glow, but if I rotate the bulb just a little the light goes to full brightness and will stay on until I turn the switch off but then the light will not come back on or even have the light glow at the ends, I have to rotate the bulb back to the normal position until I get the light glow and then rotate a little again and the light come on bright again. Any suggestions what to do next? I need to keep the fixture since I cant find anything that comes close as a replacement and that the conduit matches. Could the new warmer be bad since I used it before replacing the ballast? The bulb is F14 T12.

Fluorescent Light Problems