You’ll never be asked to pay for a visa using:
cash
money transfer
Contact Action Fraud to report visa and immigration scams. You should include:
a copy of the suspicious email you received, the sender’s email address and the date and time it was received
details of what you sent in a reply, if you replied - for example whether you sent your bank details, address or password
You can also report suspicious emails, letters or telephone calls to the police through Action Fraud.