Absolutley nothing
On arrival at the airport we went straight out to wait for the shuttle to the car rental in which the confirmation email clearly states the rental company will have a shuttle running to and from the airport every 5-10 minutes which was not the case. I had rang the rental company multiple times only to have the phone put down on me, and waited for nearly one hour in order to be collected, taken to the rental company and then to find out the car i had booked from Monday to Saturday was not there anymore and that we had missed the time slot to collect the car. In my opinion, this is not really a service worth in excess of £100 and after messaging the rental company i have found out they have no intention of reimbursing this money either. I am extremely frustrated to hear nothing can be done about this.