Sounds like you had a great game here Updraft
It kinda depends on what you did, but stating from this line:
>out of 100 cities on the map guy places airport in city with my busses
This is actually allowed, cause a city is not your property. What he is NOT allowed to do is to place airports in the town which you own, but unfortunately Cities are for everyones use.
It doesn't really matter in this case if you already had busses driving around in that city, you don't own the City since it's a source for all players... This is a part of the competition on these kind of servers!
Sorry to see that you had a bad experience, but in this case your competitor was allowed to do what he did.
Blocking after that which you apparently did if I read this line:
>Block other cities.
That is NOT allowed. Deliberately blocking resources in this case is not allowed!
If I look at what kind of game you want to play, you can better go for CV games. In this type of games you are not dependant on cities or resources in cities.
Hope this helps.
Best regards,
Frank
Server Admin