Brand New Honor Pad X8 Drains Fast, Won't Fully Charge

I purchased an Honor Pad X8 tablet from the Teknosa store. I completed the installation process, and the charge was 69%. It remained at 69% for 2 days, then suddenly dropped to 1% and turned off. I plugged it into the charger, and after 2 hours, the charge was still at 1%. I left it on charge for a few more hours, and it finally reached 100%. The problem is that the product cannot be used for 4-5 hours after it runs out of charge. If I put it on the charger before it is finished, it does not charge fully. If I take it off before it is fully charged, it turns off at 1% charge. The Honor customer representative blames the charger and does not respond positively to my request for a replacement, saying "You had bad luck."