GoPro can't record any audio anymore after recovering from being wet

I brought my GoPro to the beach and it starts to moist inside the housing and then starts to malfunction, buttons doesn't respond anymore. I put the camera inside a tupperware with rice grains for a couple of days and when I used it, it was back to normal as I thought until I notice that it can't pick up audio anymore. The record button was also not in good condition.