Thinking alike and all that...
But hey, maybe she really did 'come across flyers at british embassy
It looks like this company is some sort of start up, in this link they are trying to recruit Tennis coaches in the UK , for Warsaw dated May 10, 2011, londontennis.co.uk/forums/forumviewthread_forums.php?forumid=121&threadid=7202
The first question I would ask City Tennis Club, why don't you recruit Polish tennis coaches, there are some very good caches in Warsaw and they speak excellent English.
BTW, chris.co.pl, Program and harctur all offer very well established summer camps for kids and have a good reputation.
Do you mean bestharctur.pl/bp/index.php Jonnym?