I think if you can collect all the email communications you mentioned in your post to prove that you got the wrong suggestion from CIC, then you might stand a chance on current sponsorship. But TBH, CIC may disregard whatever the evidences you provided and still deny your application, it is because on the COPR, it clearly states how you need to handle the situation like yours and one of the requirement is to ask you DO NOT LAND, if your marriage status changed. As others said here, go find a good immigration lawyer to help you on this.