Yes, you should do. We had all of our money taken from one account, just after payday, by someone who had cloned DH's card. They went on a massive spending spree online, to Next, Foot Locker, Footasylum, etc., Then ate out in Pizza Hut and Sprinkles in Wembley to celebrate! They even redirected a Next Account to our house in DH's card no., but a different name.
Our bank were really efficient. They read all the transactions out, and we simply said "Yes" or "No" to whether we had made the transactions. It helped that none of the places they had bought from had ever been places we shop in ourselves, and they had made multiple purchases from some shops (e.g. 3 orders from Footasylum for over £120 each), and we're 80 miles from Wembley, so it was clearly suspect. That total was refunded to our account, and we were sent a declaration form which we signed to confirm that we hadn't made the purchases.
We phoned Next and gave them the information about the account, but they had already flagged it as fraudulent when it was switched. When we said that DH had never had an account there, they offered to flag our address and debit cards on their system. Now, it's impossible for us to open an account remotely there. We would have to go into the store with photo ID. We wouldn't open an account there anyway, so that's good.
The bank later told us that someone failed security 3 times by phone (they thought it was DH at the time) and then "DH" went into the branch to try and withdraw money, too, but also failed security there, so it was quite a determined attempt.
Just a shame they picked poor people who check their bank accounts and notice missing money 