Crossed link computers messed my laptop

A guy called mikail took my laptop and it was warking i just wanted to upgrade my software. They kept my computer since february . I decided to ask them to give it back to me even if its not upgraded. To my suprise when they gave it back the computer could not turn on and my charger was missing. I contacted them they promised to fix it and give me my charger . All.of a sudden they are not responding to.my messages now . Jere is their address 17 Hyacinth Road Belhar Cape Town 7493 South Africa Business Hour Contact ***