a2billing / php customize

A2billing CustomerUI customise When a Customer logs into their A2Billing Customer Portal Currently, their negative balance displays. Below the negative balance is a drop down to select the amount of money you want to add to your account. You select the amount and it redirects you to Paypal. Then redirects back adding the funded amount to your account. Instead of this we want when the Customer logs in to his portal he sees the negative balance and a link below to pay that negative balance amount, that says PAY BILL NOW. NOT a drop down to select an amount. This Link to Pay Bill Now should send this amount to the [login to view URL] gateway and return marking the database paid. Just for clarity, "A2BIlling is Not currently setup to work with [login to view URL] and needs to be." This is part of this project. Please do not Bid on this project unless you fully understand the details of the project. Also do Not bid on this project if you Do Not have experience with A2Billing code modification and Authorize Gateway setup.