Hudl 2 not charging and won't start

Ok, so our hudl's charging port broken and this was repaired under warranty about 2 year's ago. then about 3 months ago my girls where playing on it and they ran the battery flat. since then I have been unable able to charge it. I have tried all the tips like hold power and volume up for 20 seconds and then power. leave it on charge for 24 hours, still dead. does anybody have any suggestions. Willing to try anything.