Brussels Airlines complaint: Lost Baggage

I told flight from London Heatrow – Zurich – Brussels to Banjul. Upon arriving I waited for almost 1 hour to collect my bags only to be told that they didn’t arrive and was shown on a computer screen that my bag was going to arrive the next day around 3, I called the rep at the office and was told to call at 5, I made the decision to drive back to the airport at 5 because Brussels flight was landing then and believed that my suitcase would have been there. I waited 2 hours only to be told that my luggage was not with the flight or any other flight and I should come back on Friday (1st Sep) and I arrived on the Sunday (27th Sep). I decided to call customer service from Brussels and a lady informed me that my bag was in Banjul and I should contact the office. The airport is well known for stealing peoples bags and getting away with it. I have the worst customer service from the airport and Brussel that ive ever had.