No answer at the call centre

There is no answer when I call the call centre. They say I need to call back between Monday and Friday 7 am to 6pm but I have been trying to reach them within this timeframe multiple times from 5pm onwards.

Everything is automated and I cannot get through to someone human to help me- I am so frustrated!

I was told that I could do the card activation on discovery.com and when I follow all instructions and prompts it says unsuccessful and that I need to call Discovery and I cannot get through to them.