Check and correct ecommerce script

I have a modified ecommerce site based on the script from [login to view URL] Payments are handled by an email which is not sending the credit card expiry date to the supplier, need this fixed. I would also like some way to test and verify that payment details are being sent without the need to use a valid credit card. I need this work done asap with no loss of data. Budget is $30 and I am ready to hire someone right away if you are ready to begin straight away.