Appropriate compensation for 8 hour delay?

Was on a flight from Chicago to Zurich on July 26th (UA3) that departed O’Hare on time, only to turn around after an hour in the air. They are offering $200 or 10,000 miles as compensation. Through research of those on here, it was discovered the plane had been grounded the prior 10 days with a mechanical issue. I feel what they’re offering is light considering the length of the delay. Anyone had experience with getting United go up their offer?