we were very lucky with this. we went to the repsol office and bought a portable gas heater. Once we had done that we explained that we did not have any gas bottles- and the guy behind the desk did the contract for 2 bottles there and then. it was just a matter then of visiting the bottle man to collect them.  Of course, this doesn't do anything to check your gas installations - so these should be checked out first.
Regards, Haze and Alan