Why doesn't my 2004 hse Range Rover crank over only one hard bang then nothing?

What is your question?

It started with letting someone used vehicle and they ran out of gas they then told me the gas tank they used found out it had urine and gas mixed!! So I then filled it with gas and fuel injection cleaner and stalled. I kept trying to start it till battery finally died.. I parked it for a week and then changed the battery and now I can only turn the key and gives one loud click as if the starter is turning and hitting hard but no crank. I did notice that the doors didn't lock it unlock anymore even my lock button inside doesn't work. Checked all fuses and all look good. I could hear a relay in back clicking when I turn the key and right now it's only vehicle and going thru a divorce so money on hold in a way!! Please help asap! Thank you...

What makes this problem better or worse?

It's a salvaged title so it was in an accident but worked great only 94k original miles

How long has your 2004 Land Rover Range Rover had this problem?

Two weeks ago