DSM Supply (Texas) Charged my credit but have not delievered that products ordered after 40 days Dallas Texas

I received their advertisement pamphlet in my office regularly.  About more than a month ago, I placed an order for some supplies for my office.  The company charged my credit card on the same date that the order was placed and told me that the order should be delivered within 5-7 business days.  A week went by and I still have not received anything.  I called to inquire about the status of the shipment.  Someone said that it's on its way.  Another week went by and still nothing arrived. I called again and was given a specific date of arrival.  That day came and gone and nothing came.  I called again and was told that they would look into the matter and will give me a call back.  No one called me since.  I kept calling and again and again, they kept promising that the package was on its way.  It's been almost 40 days since I placed an order and I still have not received the shipment.