Looking to get some help with this one.

We were traveling SAS ARN-LHR to connect to UA LHR-EWR on Sep 5, on an award flight booked through Aeroplan.
SAS ARN-LHR was delayed causing us to miss the connection to EWR.

The next available flight was the following morning, so instead of arriving Monday night, we arrived Tuesday afternoon, causing us to miss work and school.

I filled out the claim form on the SAS website, but so far my communications with them have been unpromising. The response to the form was will get back to you at some point in the distant future (8 weeks).
Trying to send them new emails- they get bounced back due to "incorrect format", even though I follow it to the T.

Should I follow it up with Aeroplan since it was their ticket?

Has anyone used online delay compensation sites that take 25% cut but promise 98% success?