Useless call centre, no alternative communication method

Useless call centre - I've dialled in four times over nearly two hours - I get kept holding ('...one of our skilled consultants will attend to your query shortly...') - after 20 minutes-odd, it clicks over to '...sorry, the mailbox for the number you have dialled is full...' Each time I dial in, I have to listen to a load of gumphfff relating to their service - I can probably recite it in my sleep - but I am no further to resolving my query. The website provides NO email addresses - I've been referred to their ChatBot and their WhatsApp service - both of which return 'I don't understand your question'. Will never make the 'Best Businesses' List. I wouldn't be surprised if they receive an premium from Telkom on incoming calls.