If you already tried (to no avail) all the steps provided in this support article:--> If your iPad won't charge - Apple Support, AND if you have already performed a "forced" restart of your iPad, as per these instructions:
- On an iPad with a Home button: Press and hold the top (power) button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top (power) button. Only when the Apple logo appears (it might take 20-40 seconds), release that button (ignore all other screens that might appear).
but the issue persists, I suggest that you contact Apple Support directly, using this link:--> Get Support , or make an appointment and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector
After checking it out, they'll give you all the available options.
Regards
Giulio