Erroneous warnings and speed restrictions

Travelling northbound at about 18:25 yesterday (11th Sept), I saw a gantry sign warning "Congestion - Stay in Lane" and a 50mph limit with the red circle border. There was no congestion at all. The fast lane was almost empty and other lanes were sparsely populated. A number of drivers around me were immediately caught by the speed cameras, which was a little unfair, as they were driving quite safely for the conditions. Others, like myself, had to brake quite hard to get under the limit, which was dangerous and unnecessary. The next sign along said national speed limit. The next sign said 60mph and congestion. The next sign said national speed limit again and the fifth sign in succession said 50mph again. After that it was all national speed limit, but by that point we had been given SEVEN different speed limits in the space of 2-3 miles. You must surely see that that is ridiculous and potentially dangerous? Can we please have accurate, consistent and safe signage? And you should really cancel any speeding fines generated by this mistake.