If your questin is about credit, then maybe you should contact a lender to get your questions answered.
If you are calling about a RENTAL property that is listed by an agency, then you should at least get a return call from the listing agent. They are obligated to show you the rental of course, but if the Landlord wants to make sure all potential tenants have good credit scores, that would be the FIRST
question that you will be asked. The agent is working for the seller if it is their listing, so they want to be sure you are a qualified potential tenant. You should try running your OWN credit report and check it out...Maybe it is better than you think. And it is not all based on whether you use credit cards or not. Bankruptcies, previous foreclosures, cponstant late payments paying your bills, etc, these are all listed on your credit report, so if you have that sort of thing on your report you might find it impossible to find a rental.
Agents generally only get paid if their tenant "picks" a rental listed by another real estate agent. Since there are so many people who do not enlist the services of an agent and rent it out themselves, it's basically a coin flip as to whether or not the tenant will pick one that will pay the agent. Even if they do choose one that wil procure the agent some commission, it's often a fraction of what they'd get if it was a sales transaction.
An agent could show 20 rental properties, and ultimately not get paid when the tenant ultimately chooses on off Craigslist. This is why a lot of real estate agents won't bother with them. There is more "hanging fruit" (commission) in real estate sales - because the majority of properties for sale today are listing via an agent - and most agents tend to focus exclusively on them (better chance of getting paid, and a lot more money involved).
They are asking about your credit score - because if you have bad/no credit - some agents will view the work they'll have to do in finding a rental to accept you will outweigh their reward. Most rental agents will try to "weed" out the people with terrible credit before working with them.
Hope that helps!
lameredawn - why not search under "Find A Pro" at the top of the page and find the name of an agent in your area - call him or her directly.
You say you do not use credit cards - hopefully you have other means that have helped you establish a "credit rating" (car payments - loans that have been paid off, etc).
If you're a current tenant, then a letter of reference from your current landlord will be good t have on hand, too.