If you are taking a degree program, it is the institutions responsibility to ensure that you have met all the requirements. If they don't have enough information on equivalence of a different institutions course, the easiest thing for them is to require you retake the sequence.
The way to get around this isn't by taking pretests (which don't mean much) it's by writing the final exams. In some institutions you will be able to do this without (full?) course fees if you are attempting to demonstrate equivalence.
That's kind of my point - they could have tested me easily by giving me some problems from a previous final, or anything else, or even talking to me for five minutes, but instead they chose the path of petty legalism by assuming since the syllabus didn't agree with their's 100%, the only way to guarantee I knew the material was to make to pay to retake the entire sequence.
I failed to mention I'd also already spent three years as a physics major and had already taken classical mechanics, electrodynamics, and quantum mechanics - so being told to retake the intro physics sequence was quite silly indeed.
It's not exactly petty legalism, they can lose their ability to grant degrees over stuff like this. This is one of the reasons that if you are transferring institutions, as a student it is your responsibility to check transfer credits. After all, it certainly isn't true that all undergraduate curriculum are equivalent.
It's a bit of a pain, but the point wasn't that they should give you some questions from the old exam but that you should actually sit the new one, under exam conditions. That resolves the problem for everyone without you having to spend the time repeating lectures etc. In the best case you don't pay full rate either.
The way to get around this isn't by taking pretests (which don't mean much) it's by writing the final exams. In some institutions you will be able to do this without (full?) course fees if you are attempting to demonstrate equivalence.