After telling conference delegates that their data-roaming charges are “screwing” their customers at the moment, T-Mobile has promised to cut its’ overseas charges.Ed Williams, enterprise strategy head, T-Mobile, dropped the clanger at the Mobile Summit in London, whilst discussing mobile data tariffs with a panel.Chris Lewis, senior analyst for Ovum, asked Williams if; despite T-Mobile’s £8.50 “all-you-can-eat” data tariff for usage within the UK, the operator still “screws” its customers on data roaming?"Completely screw them, yes," was Williams’ response.Williams; also a director of the Mobile Data Association, later said his comment was “made in jest.” He also revealed T-Mobile will be reducing its’ data-roaming tariffs later this year.Uday Kansara, senior pricing manager, later told the conference T-Mobile is planning to bring its’ consumer rates down “as the cost come down.”