insurance companies aren't always just trying to screw over lazy people with renewals, their rates can change pretty much every day based on all the factors they rate on (address, vehicle, driver experience, % decrease from ncb, marital status etc. etc.), sometimes the combination of those rates for your quote will have gone up after a year, sometimes down and there's very little the person you're speaking to on the phone can do about that.
as the other guys have mentioned, shop around, find better prices and see if they can match em with discounts (some companies/brokers can't offer a discount without you having a comparable quote from elsewhere in the market to compare it to so make sure the cover levels match up too).