Not receiving things like Notice of Rejection of Representations is commonplace, you are definitely not alone, and there is a process to get the matter reset to the PCN stage: -
You must now wait for the debts to be registered at the Traffic Enforcement Centre. This allows DART to issue an Order for Recovery to you, one for each PCN. You can then submit a Witness Statement that you submitted representations but did not receive a notice of rejection of those reps.
https://www.gov.uk/government/publications/form-te9-dart-charge-mersey-gateway-clear-air-zones-challenge-a-traffic-enforcement-orderNow, here's the key thing; you do not have to receive the actual Orders for Recovery in order to submit the above form (TE9). You can submit them once TEC have recorded the PCNs. As you have missed receiving the rejection letters it is clear there may be a mail issue, so best not to rely on receiving the OfR. So you must be proactive from now on, and ring TEC regularly, (about every 7-10 days) to find out if the PCNs have been registered. DART can only register the PCNs after the period for payment of the Charge Certificates has expired. Be careful to check this date for each CC which tells you when DART can apply.
Other thing to say is, don't try submitting TE9s before the PCNs are registered, as TEC will have no record of them and will reject them.
Finally, on the form, the "Applicant" is DART, not you.
