Poor customer service

Two ********** purchases went off my account on the 1st of December at 21:48.I called in immediately the next morning. My card was then blocked. I was then told to go in to a store to fill in a form to register the ********** activity. Mind you, they were well aware of the ********** activity was happening on other people's account as well. I was told that the investigation would take 20-30 days to complete. I followed up with emails and phone calls and the response I received was "I am not sure how much longer it would take." In the mean time, I am being charged interest on the two ********** transactions and no refund on these transactions😠