I bought a radio should i exchange it?

I was at a pawn shop, and i got a new car and it had no radio so my mom had some stuff a friend asked her to get rid of, and she traded it to get me a radio i liked. The people said if i wanted anytime i can come back and exchange it for a different one.

I really liked the radio so i got it not thinking anything. And i went home and i was hooking it up to the factory harness for now till i get a aftermarker one.

And i know all the functions of my radio wires and my cares wires i looked up diagrams. But first problem is the 12v ignition and battery wires are both cut short. And i kind of was like ok well ill live and i proceeded to hookup the wire thats supposed to be for the antenna to the constant on the harness(i dont really want my antenna out anyway i dont like the look of it.

And sure enough it worked my radio got power, then upon looking over my wires i realized that i didnt have any wire to turn the display on, so i ended up testing wires to see if any of them might trun it on, and sure enough i did but it was one of the speaker wires, so i was happy i was in business but sometimes it doesent work and sometimes it does(i guess cause its not really supposed to.

And pretty much without a dimmer wire im pretty screwed, should i just go back and exchange it for different radio? Its an Iplug which i think is a no nameish brand.

Thanks