Try calling their reception and check if they accept patients in the condition you are in or set up an appointment with a doctor at the same time. I believe you should be able to get to see a doctor immediately. In case you are unsuccessful in this, you may try seeing an orthopedic at some other clinic such as Aster. He could help reduce your suffering. As for your query how could you prove it was sports related, you may tell that to the doctor when you get to see him and the rest is up to his judgement. By the way, why do you need to prove the pain is sports related?