[rhyds]

You're basically looking at two options, either a mobile tyre fitter or a full breakdown service.

A mobile tyre fitter probably wouldn't be able to come out right away (or will charge a fair bit to do so) and the breakdown services (AA/RAC/Green Flag) will probably only have a temporary wheel to get you home/to the nearest tyre depot.

Is this going to be a new order car? Ask how much a spare wheel kit would be as an option