I think you've got your dates slightly muddled, HCA. The OP confirmed reps were submitted on 18 September, so well in time. The only issue is they were not from the person the PCN was addressed to.
So, my view (albeit I'm probably less well informed than some others) is that Kingston need a letter of authority from the OP's husband explaining that he has authorised his wife to correspond with the council regarding the PCN and to submit reps on his behalf which she did well in advance of the 28 day deadline.
Hopefully then they will submit the Notice of Rejection, following which we are back on process (and when we can look to get Hippocrates authorised also).