Help with Google Ads

We are a private ambulance company based in South Africa. Previously, our paid advertisement consistently appeared at the top of Google search results whenever users searched for the term “ambulance number”.
Recently, however, Google has stopped displaying our paid ad. Instead, the top position now shows the government ambulance number (our competitor), which is not a paid advertisement.
I would like assistance to have our paid advertisement appear above or alongside the government number for the search term “ambulance number”. Could you also please explain how a non-paid result can take priority over a paid advertisement? I am looking for someone to help me show my Google paid advert on top of the first page as below