求助：保险协议签完几天后保险公司来邮件说要加钱

我刚买了辆$18000+一般的新车，state farm保险公司当时给的报价是900，车子开回来
后又去保险公司签了协议。不料过了几天保险公司的人来了邮件，说是要涨两百。

I have made the proper corrections to your auto policy, and once process the
policy will be mailed. There were some issues with how you, and your wife,
were rated. The new premium that I confirmed with our underwriter’s will be
$1,093.18.

不知道该怎么办

现在想换一家保险公司，不知道那900元能否退回来。真是悔得肠子都青了