Greyhound adopting SA Roadlink tendencies/ I want my refund

I booked a Greyhound Coach for a trip from Durban Station to Johannesburg Park Station for the 05th January 2019 and I went to their Durban branch on the 02nd January 2019 to cancel the trip because I needed to stay in Durban much longer than I had anticipated, I got to their offices and filled out a refund form around 17H20 and i took a picture. I have been calling to find out when my refund will be deposited in my account as I was told that I would receive it after 18 working days. It's been over 20days so I decide to make a follow up on this and spoke to Vumile who advised me that in their system it shows as I missed the bus, my question to her is since I was meant to travel with my sister for that trip and she proceeded with the trip without me and we were communicating until she arrived in Johannesburg. she told me that there was someone sitting in my space so if I missed the bus can someone explain to me why my sister found someone sitting in my space when she got inside the bus?was it not suppose to be empty until they realise that I have not made it and then replace me? I want my money so let's not play games.