Bad service from gas hub in herm****

I have been getting my gas from gas hub in herm**** for a very long time. As normal I purchased a 19kg gas bottle. This time however, I got much less gas in the same bottle. The complete system was checked for leaks where none was found. I was prepared to pay for half of a new bottle. The owner/manager refused, stating that they get the bottles sealed from the supplier. Needles to say, with their actions, I will take my business somewhere else. And after a long time after I had to leave my empty gas bottle with them, phoning and even going to the office many times, I still haven't got my deposit or empty bottle back. I'm furious with their bad service in this regard.