Mark has an innovative idea. He wants to include a catering component into his business. He invites loca businesses, media houses and social media influencers to his event called "A night of Saffron". What sets Mark apart from other catering businesses will be his uniquely crafted Saffron dishes. These dishes are meant to exhibita 'taste of Durban'. He contracts with Spices Galore to supply him with Saffron so that his wife Samantha can prepare the dishes. On the morning of the event, Samantha is eagerly awaiting her final ingredient to finish off her dishes, when she receives a call from the owner of Saffron Galore to apologise stating that they are unable to source the saffron due to their local supplier in Durban not having stock of saffron. The owner notes that Samantha can check in Pietermantzburg for saffron as she has heard from a friend that saffron is plentiful in that area as the manufacturer has a store. The owner of Saffron Galore stated that it was impossible to perform their obligations as the shortcoming was extraordinary in nature. Mark and Samantha are angry as they have a legally binding contract with Saffron Galore.

You are required to provide legal advice to Mark and Samantha on their problem. You are expected to outine the relevant law, cite applicable case law, and provide a legal opinion on the above problem.