First check your own bank or shop account for the claimed charge. If you need to ask, call a number you know independently. The ‘cancellation hotline’ in the message may belong to the scammers.
A scam email does not need a link
Some messages show only an alarming bill and a prominent telephone number. The call then becomes the place where the scammer asks for information or payment. A Swiss area code and a polite ‘support agent’ do not establish who is on the line.
Watch what a supposed cancellation requires
Stop if the caller asks you to install remote-control software, share your screen or approve a bank payment. Read your banking app yourself: a caller may describe a payment as a ‘refund’. Do not grant a new device access because someone on the phone says it will stop fraud.
If you already called
End the call if pressured. Contact your bank through its app, card or another verified channel and explain what you disclosed or approved. If you allowed remote access, disconnect it and get technical help. Change important passwords on a different trusted device and keep the email and transaction records.
A phone number in a suspicious email needs checking just as much as a link.
Sources and further help
The linked information supports this guide. It does not imply that these organisations work with or endorse MailMigo.