>>>You deserve an explanation.<<<
exactly - i work for an independent insurance agency in north-central montana and my sister used to be a farmer's agent. i agree 100% that you deserve an explanation. this kind of thing does happen and there could be many reasons for it, but you should be provided some answers and also a chance to ask them to re-write you with a lower-cost carrier. if they don't do this, then consider cancelling and going with another agency that is independent in order to give you more flexibility and choices.
i work the claims end of it, and from a claims handling perspective some of the best out there are EMC, safeco, foremost and fireman's fund. if i remember correctly, foremost does work with farmers and might be an option for you. other good choices are travelers, allstate and progressive. from my experience in claims, these companies work well, but i am sure that there are many more.
back to the original issue, your agent should certainly be able to provide some answers and options for you - if not, then he or she is not YOUR agent, if you know what i mean.