Why was my bank account charged instead of the customer's PayPal?

Customer bought from my shop and chose payment with with PayPal. When I tried to charge it I added my business credit card information. Today I noticed that the amount was accidentally charged from my bank account. Why did this happen and how is it possible to fix this?

Thanks in advance!

Is this what you mean? Unfortunately it is not in English (but Finnish) but maybe you could use Google translator for it.. It says that the payment was completed with a Visa card which number has the same ending as mine…