cheapest and easiest way to fix it for someone with basic soldering skills is to put a QI charging circuit into it to bypass the broken usb port.
you need the 2000mA charging pad circuit then the 1000mA receiver usually off ebay for around ten pounds for both.
you have to split the case and solder two fine wires to the battery terminals then to the receiver, the wires need to be long enough to fit around the copper sheet on the back panel so it can be closed up again. just make sure you get the polarity right and the pad the correct way around.
the charger unit can then be lined up and either taped onto the back or sewn into a suitable case like the fintie slate 7 case or one of the chinese clones.
I've got four of these (all bought broken off ebay) using this mod and all work fine, I have broken the ports on two of the chargers but you just put new ones in as a fiver a year is not much to pay.
if you want a very simple way to get it working again you can also split down a regular usb cable and solder the black and red wires to the battery terminal routing it through the stylus hole on the back, you have a trailing wire but you can use it while charging much safer, you just need to make sure you use a smart charger which switches itself off