Please help to resolve the issue.

I bought online bus ticket from Johannesburg to Port Elizabeth on the 08 December 2019 between 19h00 and 22h00 through JustGo for my son (Thapelo). I then realise that it is not the bus I was looking for. I was looking for Translux. Details of steps taken to resolve the complaint: The following morning, I phoned ***, ***/111, then the lady I spoke to referred me to Thembi on ***. I explained my situation to her then she promised to call me as soon as she get back in the office to resolve my issue. She did not until I send her this message: "Morning Madam! My name is Chukudu Mphulo, I booked ticket from Johannesburg to Port Elizabeth for the 12 Dec 2019, departing @ 18h30. The passenger's name is THAPELO. I am please requesting to cancel this booking. Send the cancellation confirmation to ***. I would appreciate for your kind consideration. Thanks." She did not responded and I did a follow-up on the 11 December requesting her to refund my payment. That is when she said she will issue a voucher for me for the next trip. I told her that I don't need a voucher that will eliminate me to use my money, and she insisted to issue it. On the 18 December 2019, I send her the following message: " Good day Thembi, I am still requesting you to do the right thing by refunding my payment. I have nithing to do with this voucher. Details of my account is Standard Bank, Account 1............. If this is not resolved in two days , I will take my request to another step. Hope you kept and recorded all our conservations. Thank you". What outcome proposed for this complaint? I requesting the service provider to refund my money to the account details sent to her. Till now, the service provider is not in touch with me. Please help me to resolve this.