Ok so I have a big muff NYC version with the 3.5 mm back for power supply, I don’t have a power supply and went to the music shop and they couldn’t help me out unless I spent 180 on a power box, the suggested a electronic shop to get one. Now here’s my problem when the server at the electronics shop tested one he put in a wrong polarity plug and now the pedal won’t give any effects. The light comes on and it will bypass the tone but when I hit the pedal I get nothing , no distortion just silent air

Is there anything I can do to fix this. I really like this pedal, and cause I’m all the way down under the pedal cost $270 brand new… Please somebody have some good news