Premio Tablet not charging

Bought the Premio tablet on the 25th March 2015 and it lasted only 7 days, the battery couldn't charge for days I kept it on the charger but it wasn't charging to 100% took it back to Ackermans on the 8th day, was booked in and 2 weeks later they called me and I got a new one. The same thing happened to the second one, it's the 2nd week since I have had it but I am having issues with the battery again. I have kept it on a charger for 24 hours and it goes from 7% to 6 % when I check nothing above 7%. I regret ever buying this brand.