My wife bought an Acer PC from Currys and because it had an hdmi display port had to buy a TV to use with it. The salesman attempted to sell her an insurance/service contract with it which she refused. He then said he would give a COMPLIMENTARY months cover on a contract in case she had any problems connecting the two, by the way I am an IT professional hence the original declining of a contract.
The item was paid for via a credit card and the amount verified by PIN was correct. A month later a charge of £6-50 appeared on her credit card which it transpires is for payment for insurance/s