If I cancel the debt on a card at an institution at which I also have another card, will that institution also cancel or call due the card that I have not cancelled? Or would other institutions at which I have cards hear about my cancellation at the first one, and cancel those cards?

We have never heard of Visa or any other credit institution cancelling, freezing, or restricting any remaining cards that you have not cancelled, for any other Liberty customers. The logic is this: even if they learn that you have challenged the illegitimate debt on the other cards, as long as you’re still paying on the one card, why would they shoot themselves in the foot? It’s pure gravy to them . . . so they’re not going to stop you from keeping that account open and continuing to send in those payments.