Sanjay Bandhniya We implemented similar functionality in the past. In the implementation we extended the login page and provided a "Contact Us" link.
On click of the link, a html (iframe) form opens and user provides required details and click submit.
We implemented a POST Webscript which authenticates as a "guest" user. The web-script validates the inputs (character limits, XSS Attack and SQL Injection types) and saves the details in a dataList node. If input validation fails it cancels the requests.
We implemented an option on Share Admin Console to display the data list as a table so admins can check the submitted requests and export as a excel/csv.
We had two levels of validations, one on html form itself where we limited the characters user can enter and validate harmful content and second level was on web-script side (as it is accessible by guest user).
You can implement on similar lines if that suits your requirement. Make sure you have necessary validations of user inputs.