If I buy a lifetime, fly anytime ticket, and use it all the time, you don't get to call that abuse. If I use the maximum physical quantity of something, for which I have purchased an unlimited supply, that is not abuse. If I am in breach of contract, then I am in breach of contract, but that's not abuse. Abuse implies that you don;t like what I'm doing but I'm not in breach of contract.
Calling something abuse generally means that I've found a use of the service that you didn't forecast for and despite being contractually acceptable, it means you aren't getting the advantage you thought you would from the contract. Expecting me to not use the service to my full advantage is naive at best.