Appalling After Sales Service - I Own a Car but Don’t Drive It.

I bought my car on the 26th of May, it turned out it had a faulty head gasket and I sent it back to be sorted out. It is now the 3rd of August and nothing has been done about it. I’ve contacted them numerous times, I’ve sent countless emails and I’ve personally gone into the branch for assistance, but still nothing. I own a car that I’m not driving, is sitting at WebuyCars PE and I’m paying an instalment on. It’s an issue they admit was their fault, but they’re still trying to be cheap and go through my warranty and get they keep getting denied cause it should be out of their pocket. I’m at my wits’ end and my last resort is taking this to the Ombudsman.