Item paid for but never delivered

On Dec 8, 2017 I purchased a backwash tank online from a store which showed they had stock available. Stores closer to me showed no stock available, which is why I had to buy elsewhere. After having to phone again and again and again and again, they finally told me that they actually did not have stock, but would get one to me ASAP. I personally checked with other stores from Herm**** to Port Elizabeth who did have stock and said they could send if the store I bought from would just let them know to send one down. After many, many, many more phone calls, messages, promises & unreturned calls, they said they had managed to locate one and I would get it on the 15th December. Many, many, many more calls, promises, messages & unreturned calls later - they promised I would have it by the 22nd. Then it was in the first week of January, and so on and so on. I received a mail yesterday to say that they had cancelled my order and would refund my money!!!! I DO NOT WANT THE MONEY, I WANT THE PRODUCT. I have waited extremely patiently for 7 weeks and this is what they give me. Completely unacceptable and I want this sorted immediately.