there is a possibility that these drivers could get back the fees paid by taking the company to a small claims court.
the fee for removal of a wheel clamp should be of a reasonable amount, £295 is to most drivers a weeks wage for 40 hours, hardly a reasonable amount.
at the moment there is no legislation actually in place, only guidelines.
the guidelines suggest that any release fees should be in line with the local councils own charges for the same.
the council in the area will have a set scale of fees for the release of wheel clamps, if the driver or drivers were to contact the local council and ascertain the release fees then they would have a much stronger case.
the fee for a small claim is about £80 and citizens advice will probably help.
of course a stronger action by more people could result in a better advantage for all.
if the drivers feel strongly enough they could form a consortium or group and make a legal case in the courts and thus could probably bring about a judgement overall that way every driver clamped afterwards would know what rights they have.
another option is to blockade the forecourt or the service area of any services that operate such a clamping scheme, or park in the entrance way and they cannot clamp you, it might also be worth noting that should you be parked near to an exit or entrance they must allow you to move the vehicle as you are causing an obstruction, they should also advise you that you are parked in a restricted area before wheel clamping your vehicle if you are in it, if you have your engine running then they should not clamp you at all and should allow you 15 minutes to move away.
all motorway service areas allow 2 hours free parking, it might be worth checking the tacho and the time of issue of the ticket, it is also worth obtaining pictures of the area you were parked in as clamping signs must be visible from anywhere within the restricted area.
it might be worth checking out the british parking association website.