How do I stop Wordpress Form Maker from adding "amp;" to my url?

What I am trying to do is add my PayPal link to a submit button on a form. The form maker I am using allows me to add a custom URL that redirects the user to that custom URL when they click submit on my form. The problem I am having is when I paste my PayPal URL into the redirect section and test the form, the link that I am redirected to when submitting the form has "amp;" included in the URL.

My question is, is there a piece of code I could add (or delete) in order to remove this extra piece of the URL? And if it is possible, what do I look for in the plugins code to prevent this "amp;" from being added to the URL?

For example, when I click submit, the button click redirects me to something like
http://ift.tt/1OMfemy
But, the original code that links to my PayPal page is http://ift.tt/1P5gRra

It seemed very simple to me at first that I would be looking for a redirect but the code files are in php and javascript, and I only have a basic understanding of html. I am using Wordpress and the plugin is Form Maker Pro.

I have contacted the makers of the plugin and they did not provide me with a helpful response. They told me to add my request to their submission section and wait for people to vote on it. If it got enough votes they would look into it. I have done this submission but I would like an answer beforehand, especially since there is a chance that it won't even be looked into.

via Chebli Mohamed