Refund

I took out a contract with Neotel and paid a once-off fee for a WiFi ****le. Should he reception not be good at my home I could give the ****le back within 7 days and get a refund. I gave the ****le back within 1 day and was told I would get my refund within 21 days. I emailed my termination letter on the 15th of July. It is now the 7th of September and have not received a refund. Karthigasan and her team has been promising me my refund weekly but nothing is happening. This is unacceptable!!