The sissor hinges on bottom of upvc window has snapped off. How to repair?

The bottom hinges of the upvc window has completely broken off. The window is currently held by the top hinge only. Do I need to contact specialist window repairers to fix this or can I get replacement parts from a DIY shop and fix myself? I have never seen this before and am unsure how this could have even happened?

Thanks in advance for any advice/recommendations.