When i enter in room and try to upgrade a plane - the basic plane its writes to me " This will increase the top speed of your airplane. Upgrade it now? It will cost 7500" When i click "ok" it write "It will cost 7500 Do you want to proceed?" Again i click "ok" and nothing happens my plain dose not revive any upgrades. i Have 15 000$ and the sixth rank
P.S. its same with parachute

It should work. I had a similar problem when upgrading a plane's speed. Try exiting the game then refresh your data connection then open back the game and see if that helps, it worked for me.

I tried that I also turned off and on the phone few times and reinstalled the game there is no result
I'm using windows phone 8 if that matters

first of all...why post in the aircraft section? there's a section for help called "dogfight support"

Now its in the right place.

Great but i still can't buy anything

If you are using windows to buy game credits, try buying points with an android device. I had issues with purchasing with my wimdows and had issues. Using my android went through with no problem.