Improve English lanague on the regulator site errors to better explai…

Created by: seamuslee001

…n the error

This aims to try to improve some of the english languge in the error messages that have been reported by AO staff. @JoeMurray @monishdeb I would appreciate if you can review and see what you think of the change. I'm not certain it is the best langauge but it is what I can think of right at the moment