Not happy about We Buy Cars

I bought Renault Kwid in September 2022 from we buy cars South gate and this was through their in-house finance, I collected the car on the 7 and they explained that the car is in very good condition on the Dekra report, however 10days after I collected the car on the 17 September 2022 I started to experience some funny sounds when reversing the car, I thought it will stop when time goes by but it continues until this other day I started to feel like the car is losing power and it was the 14 October 2022, I reported the matter same to the guy who was assisting with sale process so because it was Friday the guy then responded on Tuesday that I must lodge a complian through their website, the complain was lodge on the same day then the following day someone from their client service call and then he said I should take the car to one of the work that they work with and he said I must take on the 21 September 2022, I took the car there on that day and later I got a call from the guy who was assisting me at the work shop then he told me that the car has a problem on gear-box and the clutch and he also I advise that he need to take the gear-box the specialist, immediately after that call I called John Wilkson from We buy cars and explain the issues and he told me he will instruct the guy from workshop to make a claim on warranty and the car will be fixed and I must not worry, since I left the car at the work on the 21 October 2022 there still not clear explanation of when I should expect the car, everytime I call we buy cars they tell that John is busy and he will call me back and he doesn't call I always have to go after him for an update and imagine I'm paying for the car that I don't know whether it will be fixed or not and when it will be fixed I also don't know because on the 7 November 2022 I called the guy from workshop and he told that the claim was declined from the warranty and they said the car has an active warranty with the manufacturer and mind you that the gear-box was out and taken to specialist for further diagnosis, I tried to call John to explain the issue and one of we buy cars customer service agent to me that John is busy on another call and they took my information and they said they will call me back, John never called and later that day I lodge another complain on We Buy Cars website then he called me later and he told me that the car Will be fixed I must not worry and he requested a quotation from workshop so that he came ask Renault for their contribution, quotation was sent to him on Wednesday 9 November 2022 from the workshop but he never updated me about the way forward from that day until today Monday 14 November 2022 I called their customer service center and spoke to the lady and requested to speak to John, however the lady told me that John is busy and she will ask him to call me back, I insisted and told the lady that I will hold because everytime I call you say he is busy and he never call me back then the lady told me told to hold while she check what could be the issues and after some few minutes she told me that they still waiting for Renault feedback on contribution and when are they going to respond she don't know..... In conclusion We Buy cars I want that cars fixed buy the end of this week I'm giving you until 20 November 2022 and if not fixed keep your car and reverse every transactions you have made under my name and I am going to lodge a complain on MIOSA if the car is not fixed by the end of this week and please tell your finance stop deducting my account if that car is not fixed by the end of this week and note that I am not a fool that I will wait for Renault to respond you and when I don't know.... Not happy at all