Apple can charge you for a software issue for example, but they can't if the device is faulty. The way they can get money from you is to make the phone call expensive. However, solve this by claiming it back, going in store or going to www.saynoto0870.com, to find a free or geographic number (one of the best sites on the web for UK peeps!).
I am just saying that they can deny to take the call until you purchase the service call or AppleCare if it is still available. Most of the time Apple will take the call anyways as a goodwill gesture, but once they find out that AppleCare is expired (or if within the first year without extended AppleCare, after the 90 days support) they can refuse service on those grounds. I have had it happen (as there was a screw up somewhere), and they didn't want to take my service call for my server, but they made a goodwill gesture (then they found the applecare number and were fine). Apple is a good company, but the laws do not make them give you free support or service on the phone and don't always back people like they hope (which is why lots of people are being denied claims for the faulty NVidia GPUs. Due to not being able to run the verification test.) There are loopholes for everything.