LT CARTRIDGE - Refund not initiated

I had placed an order for Logitech H*** USB headset on Aug **st. I got a confirmation receipt but after many days, I had not received courier details. I called them multiple times for many days and on **th September, they finally answered and said it would be shipped within a week. Again, i called them multiple times for many days, and on **th September, somebody answered and I asked for cancellation and refund. They said they will send me an email and initiate the refund. Today, it is **th September. I have called them multiple times on many and no response.