Please Help with Airlines 2

Anyone else have this problem...
In the manual, it says that you can buy stock in "non-airline" companies. It says that if you own 100% of any of these, then you have the option of shutting them down. My devious strategy was to rush to open a route to my competitor's area, buy 100% of the non-airline companies in his region and shut them down, making it harder for him to be profitable. The problem is that I keep buying stock, and more gets issued on the open market. There are several companies now that the data screen lists me as greater than 100% owner. I also don't see any buttons that allow me to shut these companies down. I have tried pointing this out multiple times to take2 tech-support, even including the flaw that accounts for more than 100% ownership of a company. I keep getting the response that they do not provide strategy tips. Talk about worthless. Anyways, if anyone else has this game, please respond and help the "new guy" out.

Thanks

Mike
North Carolina