Just a question regarding my FB Plus renewal

Hope you are all enjoying a holiday break before the New Year.

I just have a question regarding my FB Plus renewal.

I have funds in my wallet that I thought would cover it and I have it set to "apply FB Wallet funds", however I see the charge went through on my credit card.

I would just like to understand for next time if I did something wrong or maybe I did not have enough funds in the wallet ?

It is not a problem, I just wanted to use those funds for the purchase.

Thanks in advance...