If you have a problem or complaint on the day, you must bring it to the attention of the organisers' event staff at the venue as soon as possible so they can try and resolve the issue for you.
What the supplier at the venue will always make explicitly clear to you when making the booking and once confirmed, is that if there are any issues you experience on the day, then you are to raise these with the supplier before you leave the venue. In almost all cases, they will be able to resolve any issues experienced on the day there and then.
As there will not be a representative from TrackDays on the day it is vital your complaint is logged and you take the name of the member of staff you dealt with.
In general, we consider it unreasonable if you take no action during an event, and then log a complaint at a later date through one of our customer review channels. In such circumstances, we will unlikely be able to take the matter further.