1. Dear *****, you would be very foolish to allow SAGA to pay this claim and have you bear the costs of the accident when you were not at fault. Accordingly, I would advise you to get a solicitor and to formally write to SAGA and make clear to them that in no circumstances should they admit the claim. If necessary, you should issue legal proceedings against the other driver. I am very surprised that SAGA would admit the claim when the other driver mounted the pavement. It beggars belief that they should hold you liable in such circumstances. However, you need to be proactive here.
2. Get a solicitor involved and show you are serious and mean business. Whoever is handling the claim at SAGA is merely taking the easy way out. Essentially, they are admitting the claim before they have heard your account. So, write down an account of the accident and have your solicitor go through it with you. This should then be sent with a covering letter to the insurers with a demand that they don't pay out.