(Reuters) - At least seven vendors have given Wells Fargo & Co a partial refund for their services after bank executives pressured the contractors to return 2.5% of revenue earned last year, according to sources familiar with the matter.In a bid to cut costs to offset higher regulatory spending, Wells Fargo gathered about 14 of its IT vendors in Charlotte in July and asked for a rebate for 2018. In doing so, the bank claimed the vendors had benefited from increased business from its various..