Don't know how to write to Control Point

[bin2ai]

I am having difficulties getting a notification's "appID" using the control point characteristic.
example. "com.apple.facetime"

This is my current understanding of how I can obtain that information.

Once a notification has be received I get the notificationUID and pass it into the control point characteristic's write value function. Based off of the ANCS documentation site, the format should be [commandID-notificationUID-attributeID].

From this threads ANCS code, I declared the pControlPointCharatersitic globally & statically (instead of inside of the myClient class) but when we use the writevalue() function it hangs. Is there another approach to obtain ALL OF the notification's information?

example of how I am currently trying to implement it.

1. new notification received
2. enters function "NotificationSourceNotifyCallback"
3. scrapes uint8_t *pData for the notificationUID (pData's last 4 bytes)
4. requests more data from control point by sending [1-notificationUID-0] to (NOW Static) pControlPointCharacterstic object function, "writevalue".
5. hangs, and doesn't exit writevalue function