Outstanding balance on Zoom

Hi, suddenly my zoom account has been downgraded to a non-paid account and it also shows an outstanding for approx $30/- does any one have any idea, what this could be about?

earlier last week i checked it showed my plan validity till June 24. And suddenly it's downgraded and i don't even have access to live chat with customer support. 

Can someone guide me with this.

Thanks in advance.