O2 My prepaid S not renewed

Hi, I recently got a simcard with my Prepaid S plan and after 28 days, as expected, I received an sms from O2 on 14 June that my Prepaid S plan was extended until 11 July but nothing actually happened - I wasn’t charged and data & minutes were not updated. I added a datapack L for now to have some internet at least, but I don’t understand why my S plan wasn’t renewed on 14 June even though I had sufficient funds (over 14 euros - more than needed for the My Prepaid S plan). 

Looking forward to your help, O2 team!

Thanks