They had a problem with the display cable and it can’t be easily replaced since it’s soldered to the display.
You basically just need to get an entirely new display even though it’s just the cable.
Additionally, some shops will resolder the cable, but it’s not a long term solution.
Even replacing the display by Apple is not a long term solution because they replace it with another display that has a cable that’s slightly too short and will eventually break again.
So the only real solution is to buy a new computer.
Look at the 2016 MacBook Pro.
They had a problem with the display cable and it can’t be easily replaced since it’s soldered to the display.
You basically just need to get an entirely new display even though it’s just the cable.
Additionally, some shops will resolder the cable, but it’s not a long term solution.
Even replacing the display by Apple is not a long term solution because they replace it with another display that has a cable that’s slightly too short and will eventually break again.
So the only real solution is to buy a new computer.