Samsung Galaxy s5 keeps on saying that its charging when it's not?

So I dropped my phone in the toilet last night and when I fished it out and dried it off, it started intermittently saying that it was charging and not charging. The light comes on and the phone vibrates to say that it's charging about 4 times a minute. What do I do to get this to stop? I tried plugging it in to the usb charger but it doesn't register as charging. I don't need it to charge through the usb because I have an external battery charger. How can I get it to stop falsely saying that it's charging? I do NOT want to pay to get it repaired. Last month I spent $200 on a burnt out LCD screen.

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