The phrase "actually insisted" is correct and usable in written English.
It can be used to emphasize that someone firmly requested or demanded something, often in contrast to what might have been expected.
Example: "Despite the objections, she actually insisted that the meeting take place as scheduled."
Alternatives: "firmly insisted" or "strongly insisted".
He actually insisted on sharing the writing credits for it, so he must rate it.
(Johnson indignantly pointed out later that Kennedy had actually insisted on shooting two deer, one more than etiquette required).
Jane Welsh Carlyle, his formidable wife, wrote that upon finishing "A Christmas Carol " her husband "was seized with a perfect convulsion of hospitality, and actually insisted on improvising two dinner parties with only a day between").
(Johnson indignantly pointed out later that Kennedy had actually insisted on shooting two deer, one more than etiquette required). But although he was persuaded by his editor to tone down the episode and move it 150 pages into the narrative, Manchester still portrayed Kennedy as "looking into the face of the life he was about to take", and being traumatised by the experience.
Huhne said: "They went out and put out leaflets or sanctioned leaflets which were personally attacking Nick [Clegg] for going back on the tuition fees pledge, even though they had actually insisted on that as part of the coalition agreement and making the coalition work".
Not only did I assent at once, but I actually insisted on going with him, wearing madras shorts and an old shirt and ducking beer bottles.
but few scripts or languages actually insist on capitals.
He might actually insist that journalistic standards be upheld by everyone who goes on air.
I actually insist that people read him and write about him!
In Test Airlines they actually insist that the pilots have passed a test so that they can fly a plane.
That may be a better reaction a lot of the time, because you can't actually insist that everybody live up to your standards.
