I work in the television and film industry, experience is everything, learning the trade and confidence will put you ahead of everybody not a degree. Work for free if you have too, there are plenty of people who will take you up on the offer especialy as all the budgets have been slashed, if you can drive that is the best in, as the first thing people are getting rid of is couriers and expensive drivers.
Where a 3rd will not help you is trying to get any other job but most employers just want a degree in anything, any grade, however there are too many people out there with better grades. But it is not the worse or the end, can you resubmit any work? do you have extenuating circumstances? Or take a year out and work on your portfolio.
The film industry is hard work and you will not have a life outside it, did you get a 3rd because your just not passionate about it, if so I would rethink your choice of career, because it is a hard place to be if you don't love it.
I was in a similar position and have now applied for a MA on a different route (not media) to my BA (not media)and I am alot happier.