Billing for iCloud?

Hi, I was now just going through my credit card and saw that surprised me that you have charge me for 147,52 $ You bill me 4 times during last month, August. I don't have any idea why you do this. I had the understanding that I pay only once a mont for more Gigs on you cloud. Can you tell me what's going on. I need some explanation.

Thank you, best, Thor