FYI Android is an Operating System or software that does functions as the core of your phone/tablet device.
If your screen is broken then you have to specify what make or model is the device. Android can function in most devices from different vendors e.g. HTC / SAMSUNG / QUACOMM and so on.
In the CBD of HARARE there are plenty of shops that can fix the generic popular brands LCD's or Glass Panels of your touch screens. The best place with many cellphone techs is at GULF complex but the quality of workmanship is doubtful sometimes depending on who you deal with or where you met them. Do not trust those who stand in the corridors.. I would try Ximex Mall first because there is a shop that has good spares & they know good techies too. You could bargain from there.