Delete a previously scheduled SMS
The account number of the account to transfer the credits to (available in the web-based UI)
A Hashtable with 2 keys: 'scheduled_id', 'status' e.g. result.get("source_credits_after")
String: The unique ID of the scheduled message.
The status of the message, i.e., DELETED.
Specific error codes:
The provided Resource ID is not valid or is malformed.
This can have multiple meanings: either
1) the scheduled message id doesn't exist or belongs to other account than the one using the REST API;
2) the scheduled message has already been sent and, as so, can't be deleted.