Broken promises - why won’t they come back to me?

Extremely frustrated with Yoco customer service. I have been trying to resolve an account issue for ages. On two separate occasions I was told that they would look into the matter and call me back. It’s been more than a week (7 working days) since the last interaction and no call has been received. I have also just spent 10 mins on hold to their customer services line. No one has answered and their call back function isn’t working and hasn’t been working for more than a week. Because the situation is complicated I need to speak to someone and working through the app doesn’t help me.