Sorry to here this.
If it is failing to do what was advertised, and if you complained early enough, AND the dealer hasn’t been able to fix it (they get one go, not lots of attempts to fix) then you should be able to reject. The law is quite clear, selling dealer has to fix it in one go, saying they are waiting for manufacturer isn’t relevant (your sales contract is between you and dealer). Any commercial contract between dealer and Skoda is their problem, not yours and doesn’t change your rights. How the dealer gets refunded by Skoda is not your problem and no reason to delay remedy to you.
Don’t let the dealer try and get away with making you accept a bad deal, you are entitled to your money back (less an amount for usage, say same per month as a PCP payment). Not obliged to get an exchange or replacement, and are free to take your money to another dealer (or another car brand).
I suspect the dealer will be very selective in what they tell you, try and suggest anything else, and avoid you returning the car, until you put both sets of the keys on the desk and ask if they would like your debit card to process the refund (bit drastic, but a good way to show you are serious). You are not required to agree to a non-disclosure (gagging) agreement to be refunded.
Others might also like to be aware of distance selling rules, if you ordered remotely (phone, online etc) get 14 days to reject from delivery, and won’t be any deduction of price.
If you get a chance, let everyone know what outcome is, or what you have chosen instead.