Though the icon is showing calls over wifi, I cannot make it over wifi.

[Android Central Question]

I have an unlocked S9. Carrier T mobile (prepaid). When I make a call, it's saying "Congrats, you've made your first call over wifi", but actually it's costing me from my prepaid account. How to fix this? Please help

 

[bbgpsuser]

Apparently T-Mobile still deducts your account even if you are using Wifi. https://support.t-mobile.com/thread/142186

 

[lucianus_luciferus]

Yeah. Sad but true. I think all carriers do it. I don't know one that doesn't