Wrongful transaction

On the 21/10/2019.i tried to book my family to fly from Johannesburg to Cape town with Mango airlines with my phone.The transactions could not go through and declined,so i went to another airline and i was able to buy the tickets. The following day i got two sms showing that mango deducted money from my account for the declined transaction from the previous.both transactions where an amount of R2870.50 each. I was devastated and tried to call but each time they sent me to someone who can help me yet no one does. I sent an email and got a response 3 days later stating i would be refunded in 48 hours but nothing happened. Its been almost 10 days now and no one got back to me,ive wasted money on buying airtime to call but it doesnt seem to help.im still waiting for a proper response and my refund. Ill make my way to the cape town office and try to get answers. Im very angry and disappointed as i feel ******.

Please help