Pay back all my money!!

I requested a refund for a product that I had purchased that was less that was unacceptable health wise it gathered rust. I was sent a portion of my refund, none of the customer service people have been able to give me a reason as to why here was a shortage. I have been given a run around by this business for 9 months now. Please can I receive the balance of the credit that is due to me. Had I been the 1 owing the institution I would receive calls each day of the month until I have paid it all, may I please be afforded the same courtesy.