Refund of payment

Hi there everyone. On 12th January 2020, I decided to get a WiFi broadband at my house since the older one isn't working the way it was promised. So on 12 January, I called a network company and asked them to install the WiFi network at my home for which I made them a payment of Rs. 1500 (including installation charges). They told me that the WiFi would start working the next day. I called them regarding the non functioning of the WiFi and asked them to refund my payment to which they agreed. It has been 12-13 days and till now the refund hasn't been received. I need to know how should I proceed to complain about them? Also the process that needs to be done for consumer court.