Why is my tablet charging so slowly?

Hello, I have a lenovo tab 4 10 (x304f) that was working fine until recently. I sat on it by mistake and the screen cracked so I sent it for repair. Also my charge port needed to be pushed up to work so I also told them to fix it and replace battery. After I got it back everything was working fine. But, charging took 26hours from 20 to 100. What is wrong? I sent it for repair again, they changed the port and same thing.So is it fixable. Also the touch screen sometimes doesn't work and I have to reset it for it to work. So any advice is appreciated, thanks! Also yes, when im using it while charging, it drains battery instead of charging, it charges only with screen off.. any help is appreciated!