Never Fly Mango

We booked a flight for our son in Sept 2018. Monday 26 November 2019 we phoned to confirm the booking and was advised all was in order. The day before he was supposed to leave, we tried doing a check in and had difficulty. During our call to the call centre, we were advised that the flight booking was not successful as the flight was not paid (yet the money went off our banking account). We last minute had to book a flight that cost us double the amount of money and a lot of stress. Monday 3 Dec we phoned Mango and was advised that it was indeed an error on their side, but we had to send an e-mail to the Refunds Desk - which was done and we received feedback from Scelo Mathibela | Refund Officer, advising that a refund will be made within 7 days. We send a follow up e-mail on 10 Jan 2019 as we did not receive anything. No reply. We send another today but don't expect to hear from them. What a disappointment. We will never trust Mango again.