I see you have a branch at Swindon Railway Station, but it says that the pick-up location is in North Swindon.
The website show the nearest location with available cars based on your search criteria...
This might help:-
During the booking process once you have entered your search criteria, you will see car photos (results). At the top right hand side is a drop down filter, choose "SORT BY DISTANCE”. This will shuffle the available cars based upon nearest, with a small map. The specified distance above the map is the distance from the inserted desired location to the location of the nearest supplier. Click on the little map to expand and the exact address/location will be shown.
I see the nearest supplier with available cars is at 3.51km.
In case you are with more people, you might want to pick up the car yourself and then collect the rest at the Station...(if possible). Taxis are available