lads id say it could be cheap badly produced bulbs, go to halfords get bosch ones never had problems always got ages outta them. PS make sure the retaining clip is tight when bulb is in situ, should be tight bulb shouldnt rattle.
Could be the bulbs alright, I'd recommend bosch too, or other high quality bulbs. If they keep blowing then something is earthing or there's a power surge.
Wiring problems can be a real pain to fix, they take hours but ya get a real satisfied feeling when ya finally sort it. A multi meter can be your best friend here
dont think any bulbs are that sh1t lads,
even your average ebay stuff...i have ebay stuff in my car and never blown any bulbs other than leds flickering!!!!