" i did accidentally hook the hot to the ground and visaversa"
Wouldn't explain why it worked for a day and then stopped. Usually there are a limited number of wires to work with: One negative/ground, one "memory" constant positive, one "switched" positive that turns on the whole
radio, and then either four or eight speaker wires.
Check the first three and any external fuses, you may just have a loose contact or bad connection. Then check all the speaker wires--depending on the design of the
radio, they may not be interchangeable and swapping them around can blow things out, make sure any polarity or crossed pair issues are straigthened out, i.e. "these two" to "this speaker" for each of the speakers.
It is possible the
radio was defective out of the box--that happens sometimes. But first, check the wiring.