Hello Mrs Richardson.
I appreciate your position here , but it does appear the council are unwilling to budge on their stance. You have the option to either pay it, and conclude the matters in full - whether you deem it fair or unfair, or, you do not pay it and have the matter proceed to court.
The risk of this will be the escalated charges as you potentially could end up paying more if the court deems you to still be liable. Of course the reverse is also true in that if you can prove that you received it late, then they may find in your favour and order you only pay the original charge.
However I cannot say what will or won’t happen, but those will be your only options and therefore it will be up to you on how to proceed if you are willing to take the risk.
I would only suggest going to court if you have evidence that it was indeed received later than the 14 days. If you do not, then they only have your word to rely on; as the council will surely have from their record that it was posted in time. And your word will not be strong enough evidence.
I’m sorry this may not be the answer you want but would be grateful if you could take a moment to provide a positive rating. Please do return to the site if you need any more advice. Kind regards, John.