Drained new battery

I put the key in the ignition and all I get is a minor attempt for the engine to turn over followed by a rapid ticking or clicking sound. Then the battery dies completely and nothing works.

I had it in at the dealership the first time it happened after I took the battery out and back to the place I bought it - it was completely dead. I got it back and put it back in. Someone at the dealership said it could be the key fob but that makes ZERO sense! Nonetheless I got my spare key and tried it (just to prove them wrong) and for some reason the car turned over! I had been driving it but now it is down again - same problem. This time neither key works. The battery is completely dead and the only light that came on was a door light and the car door open light in the dash. It doesn't turn over at all.

I bought the car new in 2000 and am the only driver. Used it to go to and from work only. Now am retired and can not afford a new car. I am now also disabled. It really does only have 46,000 miles on it.