OK hoping I can shed light here now.
I went out this morning, the car having failed to start all last evening, and tried again. Still wouldnt start, and this time seemed to drain power quickly and struggle to turn over the starter motor, which is something it didnt do before. Before it would turn over as long as I wanted to try it but this time it seemed to drain really easy.
All the battery talk I saw on here led me to thinking, "what if I try jump starting it from another car and see if it starts". And......It did. Started first time on being jump started.
Sooooo!!! Is it that the battery is knackered and has been slowly on the way out which is why it has not been starting for abut 3 weeks having been fine for the first 2 weeks that I had it (Ive only had it 5 weeks). Or is the alternator knackered and not charging the battery? I'm going to try and use a battery charge checker tonight to see if this is the case.
Hopefully we might be getting to the bottom of this
Nick