Zero Value Coupon doesnt display on invoice

[mrooksads]

I'm using AWO Pro with Rupostel OPC. I have a zero value coupon code that shows as 0.00 in the cart, which is what we want. However it does not show on the invoices. I need it to show on the invoice. Seyi at AwoCoupon said the invoice template is probably configured to remove zero value items, and I need to edit the template to allow zero value display in the invoice. Where would I enable zero value coupon on the invoice templates?

Joomla 3.5.0
VirtueMart 3.0.16
AwoCoupon Pro 2.4.9
Rupostel OPC 2.0.312

[mrooksads]

com_virtuemart > views > invoice > tmpl > invoice_items.php

line 170
if ($this->orderDetails['details']['BT']->coupon_discount <> 0.00) {

removed the <> 0.00 and it printed the zero value coupon line item in the customer email invoice and the vendor email invoice. It didn't print on the webpage orders invoice.

[mrooksads]

com_virtuemart > views > orders > tmpl > details_items.php

line 112:
if ($this->orderdetails['details']['BT']->coupon_discount <> 0.00) {

Same thing, removed <> 0.00 and it displayed in the order information details page