Sorry to learn about your mugging. I have stayed at the hotel Ohtels Campo de Gibraltar 2 or 3 times and not had any problem. The town is seedy in parts but that has not put me off staying. Out of interest I just looked at the Reviews for the hotel - 1,243 reviews, and only one has mentioned mugging. (or such like) It was written by JaneS dated 14 April 2017. She clearly felt nervous about walking in the dark in the area and said that she had heard it was unsafe. Understandable. The manager gave a considered response including these words:
""The subject of the assaults I do not know where it has taken, but I imagine that there are here as they exist in other parts of Europe and the world, but neither as you describe it, I am not from here, and I go and I come to the hotel walking , And when I leave at night I do not feel insecure at all.""
The point of commenting on your description bothers me now and would like to know more. If you stayed at the hotel did you mention to the hotel staff? They may have assisted with a police report. I could not see that you have posted any review of your experiences staying at the hotel. Can you give any more information about your mugging ? Time and place etc?