Well it doesn't change anything; the matter is certainly not "closed" and you continue as previously advised
Well,
@shadowliner I think you have shot yourself in the foot by replying to the charge certificate. If the council don't want to pursue the matter then it will never go to TEC, and you cannot force them to. We can try, but if they ultimately ignore you then that's the end of the matter.
For now you will have to write back as follows:
Dear London Borough of Harrow,
Thank you for confirming that "I have reviewed your case, and although your payment was made late, we have decided to accept the amount you have paid as payment in full", but this is not an acceptable answer. Please would you reinstate the charge certificate and register the debt with the Traffic Enforcement Centre so that the matter may follow the statutory process. Failure to follow the statutory process will result in a formal complaint.
Yours faithfully,