You either have to pay now or later. Later involves more legal fees.
To license Dinner at Rods you need to go to
www.warnerchappell.co.uk
There you can register and request a license for a student film. Then you just submit all your info (which is pretty specific stuff).
So register, then search for songwriter Karl Hyde. Dinner at Rods is on page 4 of the song list. Click on that and then click on license request.
Searching for the song title Dinner at Rods will give you nothing.