Technically refused reuse of an existing air-ticket till I was told the ticket is invalid and now I no longer qualify for even a refund

I booked a ticket to China last year January with Travelstart but due to delays with VISA arrangements and the agency's inability to secure me a seat according to my amendments I eventually had to book with another agency altogether. I then tried to use the same ticket to return home, I initiated communication with Travelstart around November last year with the help of my mother who's in SA via telephone but it yielded no positive or directive response. I then personally communicated via email with them. In my first email, I explained that I no longer had access to my email address that I used at the time I made the booking then proceeded to provide my updated details. I have since struggled to get a conversation flowing with the Travelstart. At any given time, I would have to send the same email at least 3 times before a response promising to respond reaches me. This continued through December 2017 to January 2018. I did receive a quote for using that same ticket in an alternative direction which cost nearly 3times the price of the original ticket. Since this did not make financial sense, I then requested to use that ticket to fly back to China. As expected, I did not get a response to this email, I then resolved that I would telephonically engage with the agency once I reach SA which I did. When I personally called the agency, they told me that my ticket had expired and all they could do for me was refund me, which takes up to 8 weeks to reach my account. I was promised that this would be communicated by email on Wednesday 7 February which never materialized. I again called the agency today annoyed and then I was told that the email was sent to my old email address. I became frustrated by this poor service and inconsistency in communication which is costing me and requested that this matter be investigated by the Manager but seconds I go I got emails from both the manager acknowledging my complaint as well as an email which was meant to inform be about my refund now saying I no longer qualify for that refund since my ticket has expired