What you must realize is that the plants you get at garden centers are not always grown from seed..They are usually a small branch from a tree that is grafted or re rooted..
In that case you will only ever get the amount of calamansi`s that would have been produced on that plant.
Calamansi trees grown from seed grow to over 15 feet high and if they are healthy will produce 100`s in a season.
That said.. Not sure how they should be grown in a UK climate??
I got loads of seeds here.. I wish I could send you some via email? I don't think I can attach them though..
