Fix issues for a e-commerce website (Lamp)

The back-end is build on a custom framework using LAMP. Please find below the issues we are facing with our e-commerce website 1..After placing a Cash on delivery order, the customer is not receiving an email notification. (we already have a setup for this, for it is not working) 2. admin/[login to view URL] - When we click on RECEIPT and take a print out, it is supposed to fit the print in an a4 size paper, for some reason that’s not the case right now. 3. admin/[login to view URL] - in order manager VIEW, the invoice is not displaying the correct info i.e grand total, mode of payment and few other elements are wrong. Screenshot: [login to view URL] 4. [login to view URL] - When we click on VIEW ORDER, we should be able to print the invoice on an a4 dimension, as of now the invoice is not adjusting as per a4. 5. After Cash on delivery purchase, the stock isn't reducing in the back-end. Screenshot: [login to view URL] 6. The text fields on the website which are mandatory are very annoying, instead of showing the feedback right below the text field, there's an annoying pop-up (alert box validation) which doesn't let you click anywhere else until you fill that field. Please change that throughout the website, make sure all the feedback is shown on the page. Also use java/ajax so the page doesn't have to refresh. Imply this throughout the website. 7. /[login to view URL] - The calculations on the checkout page are all wrong (grap wrap charges, shipping charges, cash on delivery charges, Coupon discount) We are looking for someone to do a solid job and fix all the above issues and test the website thoroughly so there are no issues in the future. The job needs to be completed in 24 - 48 hours max. I'm not willing to release any payment until all the points listed above are resolved. Regards