How to change price inside of payment field?

I have  different prices on my website: voyagestudio.ch, however can't adjust the details on the form myself. The problem is, the new clients sign up for old prices . Can you please help to adjust this very important detail? Thank you .  

You will need to change the price inside of your Form Builder. Inside of Form Builder select your payment field and click on wizard icon.

Then click on next button and on Payment Wizard: Product page select your products, change prices and save changes. 

When you change prices inside of the Form Builder, changes will be applied on your embedded form as well.

Hope this will help. Let us know if you need further assistance.