The volume won't hi up but it will go down.

Hello! I have been struggling with my Bluetooth headphones for quite some time and that is due to the fact I accidentally washed my headphones in the washer. The headphones still turned on and off and paired with my phone, the only problem is that every time I press the volume down button on the headset i can't raise it with the volume up on the headset. I put my phones volume all the way up but it doesnt help. Please if you know how to fix the buttons I will try to do it. Thank you!