Well if you are not getting buttermilk, why not try making it yourself!! The method is really very simple and just needs two things - Full Cream Milk and a Blender/Mixer.
All you have to do is keep a pot full of cold drinking water besides you. Then pour the milk in the blender jar and blend it until the fat separates from the milk and starts to form lumps. Once these lumps are formed, you can filter the mixture to get the buttermilk. Also the lumps of fat is the butter so you can squeeze the lump together and float it in the cold water pot for sometime so that it keeps set like that.
Only thing to take care is that milk should be cold preferrably out of the fridge so that the fats don't melt.
I hope you ll be able to get some fresh buttermilk this way!!
This is a very local method of separating buttermilk in my country. If it doesn't suit your purpose you might want to look at the following page: