Phone charging port melted topic

Hello, this night i was charging my phone (like every night) but when i woke up i saw my phone was off so i turned it on and wanted to remove my charger but it was stuck in the phone and then i saw the port was melted and deformed so i couldn't take the charging cable out of my phone (maybe if i pull really hard, not gonna try it yet). So i am thinking about returning the phone to LG maybe or to a store, i don't know, but as this is not a software issue i don't have to pay anything right? But another problem is that i have rooted my phone and have a custom firmware on it. So is there a way to unroot my phone without connecting to USB, and put the original firmware on it? I have BlissPop 1.5 Android 5 and TWRP custom recovery.

Thanks in advance