Air Transat complaint: Lost baggage and terrible customer servicecommunication

The airliner lost my bag on either the flight from Amsterdam-Toronto or Toronto-Ottawa. I filed the irregularity report, but the employee did not enter my contact details correctly. After repeatedly telling them to change these contact details, they did it only a week later. They already found my bag and sent an email to the wrong e-mail address and called my then inactive number (I purchased a Canadian SIM and told them). Their baggage service number(s) are rarely in operation and they do no not respond to emails. Employees all point at each other and say “I don’t know, it is not my department”. There is no superior to talk to. Internal communication is slow and inefficient and every employee tells a different story. It has now been 11 days since my arrival in Canada and they don’t know where my baggage is, even though it’s in their possession. Employees are not knowledgable and some of them are rude. A few agents were very nice and tried to find a solution.