Members of the 7,000-member California Grocers Assn. headed for Alameda County Superior Court in Oakland to attempt to halt a $3 fee a merchant must pay for every bounced customer check. The Sacramento-based CGA, the state’s largest trade group, represents food chains of all sizes as well as mom-and-pop corner groceries. The class-action suit attacks the banks’ practice of “double recovery"--collecting $10 from the bouncer and $3 from the merchant-bouncee--as illegal. B of A declined comment on the suit but has said the charges cover the costs of processing the bad check. The CGA said other suits may be filed against a few banks in the state, including Wells Fargo, that charge more than B of A.