Dear apple,
I guess you have created your online account by registering on https://www.wes.org/appstatus/indexca.aspx. What I will suggest you, log on through this website and you will get the 'current status' of your application. Even I did not receive any mail in my inbox mentioning regarding the fee payment. The reason was, when I used the credit card of my friend, money was debited to WES account at once.
However due to some website issues, WES received the payment after 2-3 days. And like anyone else I was extremely tense. So what I did was, I contacted WES on the customer care e-mail ID and later on they resolved my problem. I will suggest you the same. Please do not panic.
Have you confirmed the credit card status of your brother online? If the money has been debited from the credit card, provide all the transaction details to WES and later they will solve your payment issue or any other issue. All they (WES) need is proper documentation and the required application fees.
All the best.