One day my phone browsing was interrupted by a starbucks terms-and-conditions webpage. wtf? Turns out my phone had auto-connected to an attwifi access point in range.
What's more disturbing is that companies work with "smart device" manufacturers so they can connect this way without you ever knowing.
What if your smart tv, only ever plugged into HDMI, was connecting to your neighbor's xfinitywifi without you knowing it?
Ifaik there’s no other way to stop autoconnecting to wifi that matches certain conditions, and it drives me up the wall.
The other way I see from the other comment is to view that SSID in your wifi menu, click the (i) button next to it, and toggle "auto-join".
Ever considered just turning wifi off?
Though, given my terrible memory this particular solution sometimes comes back to bite me in the bum: Usually when I turn off wifi I forget to turn it back on again until I’m at work and I’ve already downloaded a few hundred megs of music, all the whole stupidly ignoring the 4g connection icon.
You have two options that should solve the problem. Either:
a) Tap "forget this network", or
b) Toggle "auto-join" to off
Also, from time to time, I go in and reset my network settings, which erases any networks I've forgotten to forget.