Someone called someone else with my number!

Hi all,
I had a call off someone today who was calling me back after missing a call at 10:57am. I had no idea ofc and he said that the voice was not me. He sent screenshot of my number calling. I know they can be faked, but I also know about SIM swapping. Why would they use my number to call someone? Random? I called Lebara support, and unfortunately they were not helpful.
Any info would be appreciated, thanks.

Blandy SIM swapping or cloning is quite rare, it's more likely that someone is spoofing your number in order to make spam or scam calls to other people. They will often use a spoofed UK mobile number to make it more likely that the target will either answer the call or call the number back.

Scammers go through spoofed numbers quickly so it's unlikely this will be a long term issue for you. If you're concerned you can contact customer support to ensure that nothing has happened with your account. Further information from Ofcom on number spoofing here.

Yeah, just sums up the mess the telecom networks are in still allowing spoofed numbers. Needs a major overhaul to get it sorted. Until then, it's a scammers' paradise!