NO ANSWER, NO EMAIL RESPONSE, NO URGENCIES TO ANSWER A SIMPLE REQUEST

I am trying for a week now to get hold of them to give me feedback on an email regarding a change of flight, due to COVID and my international flight changes. No answer. One soul on Facebook messenger supp**** me with a number to call after I informed them I am abroad and gave him my international phone number. I hold on for at least 30 minutes, then the phone cut off, the same as all the other calls. How difficult is it to just answer my email? Here is my email as I sent to them on 28 September 2020:

Riekie Nel <***> Sep 28, 2020, 4:09 PM (5 days ago) to enquiries

Good day

I have tried to retrieve my booking with the booking reference, but it was unsuccessful. Then we tried to phone, but no answer at one of the numbers. Is Mango airline still up and running or not?

If you are still operating, I have a few questions to ask: My booking ref is TMFPJF. Mrs. A Nel. I have a booked flight for 9 December from Cape Town to Bloemfontein and paid with a voucher. Unfortunately, Qatar airways changed some legs of our flights to South Africa, which means my travel dates are also going to change for this domestic flight. How much will the costs be to change my booking to the same flight (7am) but only on 7 December 2020 Cpt to Bfn?

Can you please let me know, as I say, no answer when calling, and I am calling for abroad.

Regards Mrs A Nel Birth date 30-11-1966

I can not wait with this information until I arrive in South Africa. What if I can not get a flight or the flight is full or anything like that? Can Mango JUST RESPOND PLEASE??