Towmhomes are all different--some are PUDs (Planned Unit Developments), and others are, in fact, treated just like a condo. All of that information should be in the documents you received at closing, one of which should be the Assocation docs. The insurance company accesses information right out of the proeprty records, so there is absolutely no reason they should not have known that yours was a townhome--don;t take that for an answer, but do go to the association and find out what they do and do not cover.
Hope this helps--good luck!
Usually townhouses and condos have policies that cover the structure as part of the HOA, and residents are responsible for getting Renters insurance (basically cover the property inside). If HOA does not cover the structure, then you buy a separate policy.