Using a bare bones iPhone, where I disabled mobile data for EVERYTHING except the approved list of messenger apps, and I still got alerts about using data.

If you have an old unlocked iPhone that you want to get working again, then check out this ChatSIM SIM Card -- but note the caveats with the limited data amount which should be enough for daily Whatsapp texting without pictures (unless if you buy Multimedia Recharges; and of course you can go hog wild with pictures on Whatsapp if you are on WIFI internet).

I have a S7 Edge Dual Sim, and I can say that it works perfectly with Whatsapp and line: the only thing you have to make sure is to disable background data (for the apps).It's amazing to be able to tell your

This company lies and is dishonest ... even following the guidelines set forth on their website to limit data

After limiting my data to 3G it worked ok

It's advertaised for having free unlimited data messages for 1 year, but it's not

Note that if you have Android, that your android phone may suck the data dry if you do not lock down the data usage on the phone.

Save yourself the horrible experience and the money "down the drain"- buy through amazon if you believe the hype, so that you have recourse to their "A-to-Z guarantee" if the chatsim fails as miserably for you as it did for me, or don't buy it at all!