The confusion seems to have been caused by Porsche GB sending you a warranty expiry letter.
Prior to that you had already told the OPC that you'd bought the car from Cazoo so they would know the car wouldn't have a valid warranty. As I understand it you discussed the procedure and costs involved in getting a warranty and were advised accordingly. With that and providing a build spec' they seem to have done all that you asked.
Did the warranty expiry letter offer you an opportunity to just pay for a renewal? If it did this would have been an error on their part. I suspect it was just a letter advising you that the warranty taken out by the previous owner was expiring. They wouldn't know where you'd bought the car from and that the warranty had already been voided by it being sold into the trade.
If you'd just taken the letter into the OPC and asked to renew it you may well have got it. It would have been the OPCs responsibility to check the service history and ask where you'd bought the car but they may not have done so. Sadly, now you'll never know.
Prior to that you had already told the OPC that you'd bought the car from Cazoo so they would know the car wouldn't have a valid warranty. As I understand it you discussed the procedure and costs involved in getting a warranty and were advised accordingly. With that and providing a build spec' they seem to have done all that you asked.
Did the warranty expiry letter offer you an opportunity to just pay for a renewal? If it did this would have been an error on their part. I suspect it was just a letter advising you that the warranty taken out by the previous owner was expiring. They wouldn't know where you'd bought the car from and that the warranty had already been voided by it being sold into the trade.
If you'd just taken the letter into the OPC and asked to renew it you may well have got it. It would have been the OPCs responsibility to check the service history and ask where you'd bought the car but they may not have done so. Sadly, now you'll never know.