The offence you have been charged with is a Band A offence which covers low level speeding and normally results in three points and a fine of up to 50% of your weekly income. You have been charged more, for non-attendance at court where it is your case that you never received notification to attend court. It is likely if you did, then you would most likely have attended and therefore the penalty would have been lesser. There are no laws, acts or sections to quote here, because it is simply a speeding offence under the Road Traffic Act for which you confirm you are guilty of but your dispute will centre on the amount of points and fine that has been awarded against you.
It is unusual not to have received the court date and this could be down to an administrative error which of course is no fault of your own. The police normally have 6 month in which to send the summons. If you did not receive a summons, you can make a statutory declaration. This is a written statement that meets the requirements of the Statutory Declarations Act 1835 and explains that you did not receive a summons. You will need to contact the court to arrange to make the statement. To make the declaration legal, you must read it out at a court in front of a Justice of the Peace; you both then sign the document. You must make the declaration within 21 days of the point at which you became aware that a summons was issued and you didn't receive it.
When you make a statutory declaration, the court will set aside ("void") the relevant proceedings. This then restarts the process so another hearing can take place which you can attend.
I would suggest when you write to the court, you let them know that the summons was not received, advise what your position is i.e. you admit fault but not the amount of the fine or the points and that you wish to make a statutory declaration.
I hope this helps. Thank you again for visiting JustAnswer, please let me know if you need me to clarify anything or if you have any additional questions. I am happy to help