I think others have answered well here, but I wanted to give a bit a "general rule of thumb" answer here.
Like others have said, I don't think what you said was wrong, but it does awfully sounds like one of those questions where you have to read between the lines to find the intent of the question. A common question of this sort is "What is your greatest weakness?" but they come in many forms.
When I was first starting out in the IT industry I often got asked questions which I couldn't answer because I had not encountered those situations and the question was not a hypothetical. So instead of asking "how would you go about trying to fix a syncing problem with a PDA?" I was asked "name an example of an issue you had with PDAs (showing my age a bit, maybe!), and how you determined what was wrong". I believe these questions are a part of what is called "behavioural interviewing".
What I learned then, and what I think is applicable to you is basically a twofold process.
- If possible, answer the question as is. In your case unfortunately, that wasn't possible.
- Try to determine what they're looking for, and give an alternative. Others here have already offered examples of what could have been said so I won't repeat it here.
Basically, if they're asking questions about troubleshooting product A and you never used product A, answer theoretically how you would troubleshoot it. If they ask about how you've dealt with unhappy customers, answer how you would deal with unhappy customers.