In our Online-Shop, we offer different payment options. The most important are "Prepay" and PayPal. With "Prepay" I mean customers have to transfer the money manually to our bankaccount (via online-banking or at the bank counter/machine) before the goods are send. This is pretty common in Germany and usually clear.
The problem is, although we implemented the Paypal checkout process which it's easy to use, there are some folks who choose "Prepay" and then send then money manually via PayPal and to top it all, they don't reference any ordernumber. So we have to ask the Crystal Ball who send us the money.
I search for my fault where we don't communicate the options clearly, so there are several things (icons/paypal logo) that makes it clear what to choose and why. But there are still a few people who don't (want to) understand the difference. The term "Praypay" have the same meaning for both processes. But if they use Paypal, we get the instant payment notification and it's easier for them - because it's just the paypal login and everything else is set.
Sending money manually is annoying and disturbs our straight, standardized and optimized german payment process.
Should I put on more information text and explain the difference in a FAQ (that maybe no one reads)? Should we discipline them in a) rejecting the money of the manual paypal payment? Or b) sending an automated message to the people, telling them that this way might delay the proceeding of their order and they should choose the right option in future?
Any other idea how to communicate clearly the difference?