Welcome to the club. Apparently same thing happened to me and this is the only response I got from a support ticket. Last thing I remember doing back then was checking out collection folder pets for my summoner and claiming Xbox game pass items.
And yes, that's $40 worth of SG you won't be seeing back.
Greetings ARKS Operative,
Thank you for contacting us and I apologize for the delay. On 8/5/2020, I can confirm that your character had purchased a "Collection Sheet Expansion" for 700 SG. As this is the case, we will not be able to refund the SG used for that purchase. I am sorry for this. If you need help with anything else, please feel free to contact us again.
- The PSO2 Team