Continue building payment extension (almost done) We have 2 days

We need freelancer who can continue Opencart's custom payment gateway integration. Job is almost done, but current freelancer does not answer us and we have deadline on Monday. Selected freelancer should work on weekends and provide complete solution before Deadline. Now payment gateway shows up on checkout page, but giving us error after redirect. Bank told us: "You give us wrong payment avail response. Please try the format which is shown in the bellow example: <?xml version="1.0" encoding="UTF-8"?> <payment-avail-response> <result> <code>1</code> <desc>OK</desc> </result> <merchant-trx>********** </merchant-trx> <purchase> <shortDesc>>**********</</shortDesc> <longDesc>>**********</</longDesc> <account-amount> <id>A2207F25B392134BB91314AD18669519</id> <amount>***</amount> <currency>981</currency> <exponent>2</exponent> </account-amount> </purchase> </payment-avail-response>" We will send documentation and other explanations. Thanks