Diet Coke has moved its ad account out of BETC London just three months after it unveiled its new creative campaign. Diet Coke is working with Dawson Pickering, the agency set up last year by BETC London's former executive creative director Neil Dawson and head of copy Clive Pickering. Dawson Pickering is believed to be working with Diet Coke on a project related to the recent "Regret Nothing" campaign. BETC London has worked on the GBP40 million North West Europe and the Nordics account since 2012.