Guest Care/Refunds team not processing refunds and ignoring queries

Due to the COVID19 lockdown we were unable to utilise 4 return tickets purchased with Mango Airlines. I requested a full refund as I am entitled to as per the CPA, but was issued with vouchers instead. I made contact with Mango who took their time to respond after flagging via email and their social media team (nevermind the calls that go unanswered at their call centre), however when they did, are insistent on only refunding 1 ticket based on the traveller being over 65 years of age.

I have asked what in the CPA advises and allows their decision, but it appears that they prefer to pretend like no question was asked and that it is acceptable to rather repeat the same response without acknowledging my query. I have also asked for my query to be escalated to someone who can answer me if their "Guest Care" or Refunds team cannot, however I am now being ignored. I have also not even been refunded the ticket for the traveller over 65. Mango needs to relook their definition of customer service as it is seriously lacking. We are all living in difficult times and Mango should not be exploiting customers. Withholding funds for services not rendered is ********* and completely against the CPA. 5 months later and the silence from Mango now dictates that I lay a complaint with the NCC.