+1
The council are being their usual obdurate selves, so if you want to fight this, or at least get to a position of only paying the discounted amount, (£55), you have to now ignore their letter of 19th November, and wait for them to register the debt at the Traffic Enforcement Centre. This adds £10 to the CC amount, and they then send you an Order for Recovery. Accompanying the OfR, will be a form to submit a Witness Statement. You then fill this form in, and send it off to TEC. TEC then cancel the CC and OfR and the process reverts back to the NtO stage. You can then pay or submit representations. This palaver is totally routine nowadays, so nothing to fear. It is this, or pay the £110 they are demanding.
The PCN would have been served by a CEO to your car, as it is for a parking contravention under the Traffic Management Act 2004. If they get no response to it, they then send a Notice to Owner to the name and address on the V5 Registration Certificate for the car. Presumably this is yourself ? As Stamfordman asks, is the name and address on the CC correct and identical to the name and address on your V5 ?