I wouldnt be too disheartened at not getting an interview. Even when the industry is in a boom time, people can still wait months, even years to get an interview for a half decent job.
As for your question, personally i would rather do an FI rating than go to Africa. There are still plenty FI jobs going here in the UK. You only need to look at Pilot, Flyer, UKGA etc to see theres loads of work for FI's. On top of that, an FI rating will stand you in good stead for your future career, once the airline recruitment picks up again.