Billed twice

I am a reqular customer of Mango Airlines, in fact, when flying local, I only rely on Mango Airlines. Since, I am such a well known customer, I am a bit fami**** with their policies and procedures. Over the past two weeks, I have been battling with getting Mango to refund me for missing my flight due to unseen circumstances. Unfortunately, according to them, the flight was in the past and therefore I cannot be reimbursed for it. However, I previously missed a flight and I was just given the option to book another and pay the difference, this flight was also missed and therefore was in the past as well. I cannot believe this nonsense, nonetheless, I had to get home and therefore was forces to pay another R3k. This is terrible service, as a airline, Mango should foresee that unforeseen circumstances comes up and clients should not just forfeit their funds. This is a lot of money lost and I will certainly not be flying mango again!