Wi-Fi calling is a trap (Internatiponal Roaming)

I travel a bit out of South Africa. In the history of my travel, I have always had the so called WI-FI calling service. Please note, I was told I activate it once. I have never had to call Cell C beofre I leave the country. Now I am in Kenya, making calls only from the hotel room (with full wifi)-streaming movies type of a strength. Today I get an SMS saying I have reached R4000. How when I am on unlimited package and not roaming? The so called Pinnacle Unlimited Package. No one is answering my e-mail. Even tried them on Twitter.

Careful of these guys. I will reverse this debit order until the CEO can explain to me hwat the hell this is. I am willing to go against them legally for the principle.