Not entirely sure its still the same but it used to be that if you were in the job less than two years you would get a refund of your own contributions only - the money paid in by the employer reverted to them.

After two years in the job the cash stayed in the employers pension fund, or you got a "buy-out value" that you could transfer to another pension - but you couldn't get any cash out until retirement.

So much depends on the kind of pension nowadays, you really need to talk to your employer or an IFA with all your pension paperwork to be sure.