The NDORS motorway awareness course is for offences committed on variable speed limit motorways. Sounds like that would not be appropriate in your case. As well as that, some forces do not allow a course of each type to be taken within three years.
Anyway, none of that really matters. The offer of a course is entirely at the discretion of the police. There is no right to one, no rules (just guidance) and no right of appeal if you re not offered one.
I should think here is no chance that the police will revisit this.