Hi,
I have 8 year plus experience with CTI ( computer telephony integration ) and Asterisk, Freeswitch SIP, IAX etc...
Regarding this project I can easily full fill your requirement by using open source ICTCore framework. but before I finalize my design for this task I want to know.
1. How your existing application will provide new order information / confirmation code this application ? via REST APIs vis Database or something other please mention.
2. After processing calls and collecting user response where should this application needs to put it, again REST APIs, Database or something other please mention.
Note: If you want I can design a fully dynamic message for order confirmation (but it will increase project cost a little more due to TTS engine etc ... ) for example, "Dear Denial Mark, we have received an order from your with Amount of 290 AUD, please enter your code to confirm ......
Please contact ASAP if you are interested in my services.
Regards