Hi there,
The roaming notification is automatically sent once you connect to a foreign network and begin to roam. However, if you have no usage regarding making a call, checking voicemail, sending a text, or using data then you shouldn’t be charged.
If you’re sure that there was no other usage than receiving a text SMS, then the charges shouldn’t show. If they do, feel free to message here once the bill is issued and someone will be able to look into the charge but it would have to be after the charge is issued, not before.