damaged goods

Over a month ago someone who handles baggage at Mango Airline decided to rip my bag open and take what they wanted to. After informing the airline they said they are not held liable for damaged bags. My bag was not simply damage, one of their employees decided to break the zips off the bag. It is not a case of getting scratched or bumped. After no help from the person at the airline i sent the FB page a message and they apologised and said someone would call me so they can sort my bag out. This was longer then a month ago...