Hello Rlysee36,
Welcome to the community!
Sorry to hear you're having issues with calls and text messages abroad. I understand it was working previously, however, had you changed your device since then? What device are you using? Have you verified your device is compatible with the local networks in Singapore?
As far as I am aware, the bands/frequencies used in that Country are different from those used in Canada (see here and here). Is it possible your device (and/or plan) might not be compatible with voLTE? Alternatively, have you enabled HD calling on your device? It sounds like your device is able to connect to the LTE network, which why your data seems to work. However, without voLTE, your device would need to switch to the '3G' network for calls and messages. If your phone does not support the bands/frequencies for that network, that could explain the issue you're experiencing.
You should note these forums are community-driven and not intended as a venue for customer services. If you wish to address your matter, you would need to contact customer service. If you are still outside of Canada, they do have a number to call from abroad. In addition, they can also be contacted via Live Chat, Facebook, or Twitter. Those methods can be accessed via the contact page posted above.
Hope this helps 😀
Cheers
