Dead battery

Im gonna make this as detailed as possible. 6
months ago my speakers stopped working and my
after market radio that came with the car 3 years
ago was acting funny. 4 months ago my battery
died. I replaced it and was fine until someone said
they could put the new radio I got, which was a
Sony. After two days my battery died. I made sure i
turned off my radio every time I left the vehicle.
And even let my car sit in idle for a little bit with the
radio, and lights off so the battery could recharge a
couple of times a week. I had a 3 year warranty so
they gave me a new battery and the person who
put  the radio in unplugged the wires from the radio
but left the wires that connect the radio
(installation kit I believe) to my car cords plugged
in.  A week later my second new battery was dead.
I unplugged those wires and am wondering if I get
my battery recharged  at auto zone and put it in
now will it be fine? Or should i just get a whole new
battery? Or is there possibly another issue im
missing? I was also gonna try to unplug the amp
as well.