Just found I've had money taken from Tesco Visa

[Private]

Debit card chargeback

Debit cards your money. Bank to bank
Credit cards there money. Anything else, ie retailers online or face to face
Any thing over £100.00 is insured on credit cards only look at T&Cs

Fraud is fraud. funds are returned in full but at card issuers descression, time limet not set.

Been told to also, put debit cards inbetween cerdit cards in wallet for extra safety with this new touch thingy

I am not too sure exactly what is meant by the statement in bold above but I would like to point out that Section 75 is a legal requirement for credit cards but most debit cards do offer a 'voluntary' chargeback scheme too.
Don't take my word for it, follow the link to the best in the business for this kind of information.....

Chargeback: money back for faulty goods - MoneySavingExpert