post https://api.callhub.io/v2/credits_usage/
Gives usage details given duration
Campaign Type Mapping :
- SMS Broadcast = 1
- Text 2 Join = 3
- P2P = 4
- Call Centre = 5
- Voice Broadcast = 6
If End Date is not provided details will come for only 1 day.
All Usage details are from UTC 00:00 to 23:59