The agency won out against rival agencies which included Mindshare, Carat and OMD for the price comparison site business. The pitch was called in July this year.
The majority of the billings, some £14.6 milion, are spent on TV coverage with press and radio taking up the slim remainder.
ZenithOptimedia has held the business, which is part of the BGL Group and famed for its meerkat-fronted advertising, since 2007.
The pitch, which was handled by the AAR, coincided with a digital pitch to find an agency to look after its online marketing.
VCCP, the client's ad agency, was unaffected by the review.