Turkish Airline is Not Available for their customers

My flight is today . I have been trying since MARCH 27 to gt my flight changed or refunded or a voucher issued .I am trying to get hold of them but I can't find a number to contact them on ...the one number I di find on the internet does not go anywhere .Why is it for a airline they are so so difficult to get hold off.i am at my wits end trying to get my ticket sorted out and I have been trying for such a long time too