From your description I'm pretty confident that that has happened

You have two options, either get one of those 1A charging modules and solder it to the board (IN goes to the solder holes next to the USB connector, and OUT goes to the back of the battery connector on the PCB), or send me an email and we'll sort out a return and repair!
You've obviously already learnt the hard way, but don't always trust what you read and trust what your common sense says because engineers design these things and especially for batteries if BLACK if not GND then I would never trust that engineer again
