able to place international calls despite adding block?

My address book has international contact numbers of friends and family. We have been calling using What'sApp without any issues. In past (>1 years ago), we made accidental calls using carrier instead of WhatsApp and saw spike in the bill. T-mobile was nice enough to waive some part of the charges that time. So to not repeat those mistakes in future, we requested international call block on all our lines. 

From the last month bill, I found out myself making accidental international call through carrier. I was first surprised how I was able to make the call with block in place. I found a record of account activity reflecting international block put in by Cx support last year in July. I called the Cx support about this.

The automated system prompted if I was calling about the recent international charge, as if it's expecting my call. 😀. After a brief wait, Cx support associate checked and claimed that there's no block placed on my line and offered to put a block on my line. It's not making sense but I was fine with that. After some wait, the rep said all lines are now blocked to make intl calls. I couldn't see any account activity of changes even though there is an 'international block' add-on feature on the line.

But this time I wanted to have some better evidential trail, so I requested if they could send me an email/mail about the block they are placing. Cx support claimed to have no such ability and wanted me to trust them. 😀 Well, how can I trust after all this ?

I don't know if there's a foul play. But I'm suspecting the previous blocks may have been dropped unintentionally by the carrier.

Just wondering, if this is just one off the case with me or anyone facing/faced similar issues?