The only option seems to Appeal and/or reapply

Im not sure what you applied under, You have PR but you can not sponsor under EEA rules, only under uk rules

The statement of intent mentions uploading/sending supporting documents so i doubt it is going to be as easy as they are making out (at least for non eea citizens), but emailing/uploading them might be easier than posting the massive form, we will have to see

Are you currently exercising treaty rights in uk, then apply as such

Is your partner from the EU?, as applicants from outside the UK as i understand it will still need to apply for PR under the current system ie no online applications, and the current long winded form

If you are married you have rights ie work, as an extended member you are unlikely to get work permission until your application is decided that can take up to 6 months, once you are in the uk. you will also need to produce 2 years evidence of cohabitation ie joint/bank account, joint bills and tena...

Do you have 2 years proof of cohabitation, joint bank account, joint bills etc, tenancy, they will be looking for 2 years worth, the 2 years is not written down, but is rule of thumb they use.