Delivery time getting ridiculous

On March the 15th I placed an order for a book. When order was placed there was stock available from CPT warehouse and delivery would take place no later than the 31st of March. On the 31st of March I enquired about my delivery and was told that all of a sudden there is no stock. After numerous email I still did not receive my order and still I get the same answer that they still waiting for stock. I want this order to be delivered this week and I don't care where they get it from. I paid for it and to wait a month for a book is ridiculous. I could have bought it in-store but for convenience I bought it on line just to find out that I made a huge mistake. This is the worst service and experience I have ever received