Usage credits and work mode failure today

Guys, I have a little bit of a situation here. I have 45,000 usage credits that back me up when my weekly limit is used up. It’s been working perfectly for over a year now. Today, when I was using a work conversation, I ran out of my weekly limit and instead of using my usage credits, it said message limit reached. So I tried starting up a new work conversation, and the same thing happened. It would not even let me use a new work conversation using my usage credits.

So I sent a message to customer support and they got back to me, and I’m a little bit upset. They literally told me, even though you have usage credits, when your weekly limit is expired, it doesn’t guarantee that you can continue to use work mode. So may I ask, what is the purpose of me buying usage credits then? Does this not make any sense? Does that not sound contradicting? What am I supposed to do here?

The reason why I have been buying and using usage credits over the years is so that I can continue using after my weekly limit is expired, so I am really confused right now. why customer support doesn’t understand this? This is the basic premise of usage credits