Online order - payment has 'gone missing' despite proof submitted

I placed an order on 29 May on the online store. After 5 days I queried and was told the order failed. I provided proof that the order was comfirmed on email and subsequently even called Netcash, who manages online payments obo Westpack. All parties comfirmed that the order and payment went through successfully and was not reversed. Initially the service was good but as time went by and I supp**** proof after proof of payment, they went silent. I have not received my order as yet. They are demanding my card statements but I have supp**** all the required proof.