Licensing not done

I purchased a vehicle through Webuycars Riverhorse and Kegan was my sales representative. To date my car has still not been licensed and when complaining to Kegan she gave me the number of Coastal Number Plates which is the company We Buy Cars contracted to do the licensing. They do not answer the phone and ignore emails and messages. I should also not have to chase a supplier of Webuycars, as Webuycars invoiced me for this service and have been paid. I would like to be contacted by the branch manager, or someone of higher authority who is able to make decisions to discuss the way forward. Either webuycars refunds me for this service they cannot provide, or else the service must be provided immediately. If no response is received by the end of this week I will be issuing a letter of demand and contacting the ombudsman.