I have an issue , recently i bought this bundle https://itch.io/b/653/legacy-classic-pack-vl2 , but when the payment was done i was redirected to a page of itchio with the next description:

We had an issue processing your payment

We're sorry about that. An error was encountered when processing your payment through our payment processor.

• If your account has been charged please contact support with the payment code P-5631674 and we can resolve the issue.
• If you have not been charged then you can try again.
• For any other questions or issues please contact support.

I need help 

Well, did you contact support? I've let an admin know, but they can't do much unless there's a support ticket to handle.