Why Zoom Charged only 9.80 of my 15.99 plan When I started reactivate after I pause subscription

I have paused my zoom subscription last month and my zoom plan is cost 15.99$ when I reactivate my account it charge only 9.80$. I reactivate on 29 may 2024 the renew date set on 17 June 2024. So on 17 June 2024 I need to charge 15.99$ or other price? If I charge 15.99 $ on 17 June I need to spend 9.80$ + 15.99$ for a month?