Investment in Mandela coins through Gold Investment Corporation

I invested in Mandela coins, long walk to freedom in 2008, I did that so I can cash 9n during my pension. I am on pension now and am struggling to get or sell the coins.

Cannot even access the shop unless you book an appointment.

This is a problem because if I cannot get hold of the coins or sell, my kids will struggle once I pass on.

The lady who was a broker is no where to be found not even on social media.