Contact
The publisher is Sumslip. Send a wrong calculation or a privacy request to blackningtop@gmail.com. There is no customer account to reset.
What to include
Name the page, the numbers you typed, and the result you expected. A screenshot of the inputs is enough. Do not send bank statements, card numbers, government ID numbers, or passwords.
The publisher reads mail to correct an error or to answer a privacy request. A reply is not a personal financial recommendation.