By Nelson Banya and Helen Reid JOHANNESBURG (Reuters) – Mining companies in South Africa have resorted to trucking coal to ports to meet a surge in European demand since the war in Ukraine started, bypassing the deteriorating rail infrastructure they blame for billions of dollars in lost revenue. Poor maintenance, a lack of spare parts for trains, copper cable theft and vandalism have disrupted state logistics firm Transnet’s freight rail services, causing coal and iron ore exports to fall in recent years. In April, Transnet declared force majeure on contracts with producers but with coal pric…