Yes, you most certainly can. Request copies of the data they are relying on showing the satellite connectivity, the phone connection with an overlay of the road they have advised you have been speeding on. I hate black boxes with a passion for this reason, it is very very easy for them to fail and lose triangulation of reference points (it needs three points to identify speed). I have had many a case where it appears people have jumped passed the speed of light, yet were doing 20mph in traffic through a town. If the black box loses power, phone connectivity, GPS connectivity (weather can be a factor especially rain and bad weather) - in fact, there are myriad of things that can affect the readings. Raise a complaint and take to the Financial Ombudsman Service.