You cannot challenge the CC, as the period for submitting representations is past. What you must do now is wait for them to register the debt at the Traffic Enforcement Centre, (the court without courts !), add the £9 registration fee to the £195 of the CC. They must then send out an Order for Recovery. You then have (I think), 21 days from its receipt to submit a Statutory Declaration to TEC that you did not receive the PCN.
The only source they have for your name and address is that recorded by the lease company, who would have received the first PCN, and submitted reps giving your name and address. Is this name and address correct in all detail ?
With your PCN going astray, do not rely on getting the paper OfR document, but after the period allowed on the Charge Certificate for payment, phone TEC every 7-10 days to find out if the debt has been registered. Once it has, then download the form from TEC, fill it in, get it witnessed, and sent off, by e-mail preferably.
If the application is accepted, and if the submission is within the time limit, this is automatic, TEC will order cancellation of the OfR and the CC. The matter then reverts to the PCN stage at which point you can pay or submit representations.
Find out, if possible, when the lease company receive a notice of acceptance of their representations against the first PCN, (yours is the second). Newham only have 28 days to send off the second PCN; if later, it is served out-of-time and void.