Depends on how long you powered it wired wrong… Does Windows recognize it when you plug the USB in?
If not, you probably have a couple damaged parts, but they are fixable…
If you plug the arduino into ramps and power it for a few seconds, does the regulator chip get hot? The regulator is in the corner near the power plug… And are there any lights in the arduino?
Mostly what happens is you burn up the regulator and you burn a safety diode on the USB. The regulator is simple to replace and you just remove the diode although it is also simple to replace.
Test and let me know… Then I can tell you how to replace the regulator. (You can get them from Amazon, or aliexpress, or any number of places.)