Mytrip.com Provided a Voucher Instead of a Refund

I did not receive a cash refund for my ticket canceled through Mytrip; instead, they provided me with a code that can only be used on Mytrip—essentially worthless for a single ticket, especially if you buy a low-cost ticket, as your money is wasted. Although I appealed this decision, they informed me that I would either not receive any money or would only get the code, so I had no choice but to accept it. However, when I tried to use the code, I received a message stating that it was invalid. The flexible ticket I purchased for 15-20% more was completely useless.
I request that this issue be resolved. Their website clearly states that cash refunds are available, but the application only offers promotional codes instead.