Hi, i lost a lot of money through sim swap last week when i was out of the country, how do i get my money back because i realised it was the mobile service provider's fault to process the swap even after the the agent alarted the mobile provider of suspec

My sim card was swapped at a mobile service provider's agent shop without my knowledge as I was out of the country, the agent claims she suspected the swap as the person had come another day earlier and tried to convince her to do the swap without the original ID but she declined. She reported the matter to the fraud department of the provider the same day but no action was taken, within a week from the date of the sim swap all my money was withdrawn from both the mobile payment service and my bank account, it was being withdrawn daily for seven days. I suspect it was an inside job from both the mobile provider and the bank.