Yeah, you are right that sometimes a customer service rep will not know the exact model and flavor that is being used. That problem is much more common with a run of the mill CSR than with a loan officer. So the first thing to do is before you ask, make sure that the person is a loan officer.
If the LO doesn't know, your next step is to ask (in a friendly way) if they can place you on hold while they are looking into it. You don't mind waiting, but you'd really appreciate it if they could see if there is somebody there who does know. Also fine if they research it and then give you a call back. Always good to give them examples of what you might mean, e.g. phrases like Experian FICO Score 2, Experian FICO 8, etc. and that they need to be sure this is what they'd use for this particular loan.
If getting the wrong info could be really upsetting, it's worth confirming what they say with another LO.
What you should never do is, if they say they don't know, decide that you do know. There's a big chance you could be wrong. In your case (a personal loan) you had a good chance of being right that it was the "Classic" flavor, but it might well have been the classic from FICO 98 (aka Experian Score 2), from FICO 04, or from FICO 9 -- all alternatives to your guess (which was FICO 8).
Another source of information is to start a thread in the General myFICO forum where you explain you are looking for a particular kind of loan. Explain that these scores (W, X, Y, Z) are pretty good for you, but these other scores are bad (P, Q, R, etc.) -- can anyone suggest lenders that would be safe? Then be sure to follow up with the lenders themselves and ask them as well. There are hundreds of good lenders out there and it shouldn't be hard to find a good fit -- best bureau and model for you.
Again, that's just advice for the future. Naturally it bites that you had a bad experience and I am sure everybody feels for you.
