Sorry to hear you've received some unexpected roaming charges. Have you had a chance to view the detailed billing information to see what roaming usage incurred the charges?
@altairtim wrote:... So literally there should be no way I could be charged with roam services....
Unfortunately, that statement is not correct. As far as I am aware, iPhones do not have a setting to disable roaming entirely. Android devices used to be able to fully disable roaming, however, that functionality was removed circa Kitkat if I remember correctly. The setting available on iOS is to disable roaming data. You should note that disabling roaming data does not prevent roaming for voice and text messaging. Is it possible you sent some text messages thinking they were iMessages?
Do you use WhatsApp? Are you aware that many voIP apps will switch to cellular network minutes if the data connection is not adequate (see here). Is it possible that some of your WhatsApp calls switched to the cellular networks?
Do you use Wifi-calling? You should note that some Wifi-calling usage abroad is also considered roaming (see here).
If the usage noted is indeed data, it's possible disabling iPhone's roaming data setting doesn't disable all types of data usage (see here, here, here, here, etc). I understand some of those links are dated but there are more recent other examples as well. An explanation I have read is that devices connect to Apple servers for certain essential functions so it is allowed despite data and roaming data settings disabled. Unfortunately, I don't think there's an official solution as Apple tends to deny it's an issue.
I understand you might not have intended on using roaming services. However, Fido will only charge for roaming if the services were actually used on a foreign network. Is there a setting to disable the eSIM entirely? If so, that option might prevent roaming charges in the future.
Hope this helps 😀