Hello Jappan,
Welcome to the community!
Sorry to hear you've incurred unexpected roaming charges. However, you should note the forums are community-driven and not intended as a venue for customer services. We do not have access to customers' accounts nor would we be in any position to consider your matter.
I understand this is a difficult time and receiving such a bill even more distressing. If you're unable to make full payment on the bill, you might consider trying to arrange a payment schedule. To make an arrangement, you'll need to contact the credit operations department. It should also be mentioned that any arrangement would be at the discretion of the credit operations team.
In order to prevent unintended roaming charges, it is generally recommended to disable data and roaming data. However, you should note that disabling those settings does not prevent roaming for voice and messaging. In addition, some manufacturers might allow some data usage to occur despite those settings (see here). That's why it is also generally recommended to enable Airplane and/or Flight modes in order to prevent unintended roaming usage. You could then manually enable Wifi when required.
Fido Roam is automatically enabled on Data, Talk & Text and Talk & Text plans. If you did not wish to use the feature, you would need to opt-out of Fido Roam. In doing so, your usage would be on a pay-per-use basis. You can view those rates here.
For the sake of completeness, it should be noted that while using Wifi for regular internet access will not incur Fido Roam charges, there seems to be some misunderstanding regarding Wifi-calling. I'm not sure how people have gotten the impression that Wifi-calling does not use the networks. However, that is not true. While the calls and messages do not transmit via cellular towers, they still use the networks via the internet gateway (see image here). The cellular towers and Wifi are merely alternate means of accessing the networks. Calls and messages would not be able to complete or get sent/received without the networks. As such, using Wifi-calling is technically using Fido services. However, they have allowed certain usage to be free from additional charges. All the messages and calls you receive (from anywhere in the world) will be taken from your plan's voice minutes and messaging limits. As well, all Wifi-calling messages and calls you make to a Canadian phone number while abroad won't incur long-distance or roaming charges (see link above).
If you would like to discus your rmatter and/or opt-out of Fido Roam, you would need to contact customer service.
Hope this helps 😀
Cheers
