Incompatible ink cartridges of Canon named compatible ink cartridges

I have a Canon ink jet printer which was bought in the US.  This has been a quite useful and convenient to use because the printer has functions of WiFi and scanning.  However, I was encountered with a big problem several weeks ago.  My kids used up the ink cartridges that I had purchased in the US.  I went to a Media Markt in Brussels to buy new ink cartridges.  I could not find out the same ink cartridges as I have used for the printer.  I purchased compatible ink cartridges produced by Canon because the box of compatible ink cartridges reads they work for my printer.  However, the compatible cartridges have not worked for my printer.  I emailed Canon about this problem. A Canon representative emailed me saying that the compatible ink cartridges in the European countries do not work for printers purchased in the US.  As a result, I wasted about 60 euro for the incompatible ink cartridges.  I do not understand why Canon has this region restriction policy in ink cartridges.  Then, whenever I move to another region, do I have to buy a new printer?  From now on, I will not buy any Canon applicance.