Freelander 1 won’t start

Hi not sure if anyone can help I have a freelander 1 2000 td4. Brought 5 days ago car was driving fine however 3 days ago central locking and windows stopped working which was a fuse which has been sorted how ever the battery was allowed to go flat which in turn the fob doesn’t work at all now and the vehicle won’t start it turns over and will tick over with easy start but the second you stop with the easy start it cuts out. Please help can’t use the car.