hey koram, i got the same problem too when i purchase a usb condenser mic. there's really no way to "fix it" but there is a way.
you highlight the left side where there are vocals and you right click it and copy it. After you do that, you highlight the right side where it has no vocals and you amplify it to the highest negative number you want (to erase all sounds in the right). afterward, right click on the right channel while it's still highlight and paste the left channel into it. this is how i did it and it works for me. hope it helps and good luck