Mango airlines pathetic service

My mom has a flight booked for Monday 28 sept 2020 from JHB to Durban, unfortunately the people she is traveling too has had a Covid19 scare today so we wanted to cancel the flight, after 29min of holding on the line I eventually get through to a agent, I tell her the problem to which she replies they do not do ticket refunds I must choose another date, i explain to her that we do not know when to move it to, then she tells me I need a doctors letter to get a voucher, to which I reply that my mom is flying tomorrow when must I get a ticket...her answer to me is Sorry sir its you that has the problem you must make a plan!!!!! GO TO HELL MANGO AIRLINES I WILL NEVER SUPPORT YOU AND YOUR *********** STAFF AGAIN