We were delayed over 3 hours from Tampa to Gatwick and found that BA was reluctant to accept responsibility for their delayed aircraft. Initially they said that the flight was operated by American Airlines with whom we had booked the fight; even though BA was the carrier. AA confirmed that BA was the carrier and therefore responsible. After again contacting BA they paid the appropriate compensation without apology for there tactics to avoid their responsibility.
Done give up if you are entitled to compensation.