Disgusting service

I have placed an order on the 18th December 2018 which was meant to be delivered within 5 working days and after nearly a month of no delivery, I am still trying to contact them. There is no communication from their side to say what the hold up is. I needed to follow up with them several times. I was offered a lousy 10% off my next purchase and promised that my order would be delivered last week but I am still waiting for the order and yet, no communication. How do I get hold of them??? I just want my order delivered when promised or I want a full refund! This service is disgusting