By Guy Taylor The London Underground is set for disruption this week as customer service managers announced further strike action. Members of the TSSA union will walk-out on Friday 26 April, with disruption expected on Saturday as some staff shifts spill-over. An overtime ban will also kick off on the same date, running until May 5. A strike from TSSA customer service managers on 10 April forced stations to close at short notice and the union warned last minute shutdowns late on Friday night and into Saturday morning were “likely.” TSSA General Secretary Maryam Eslamdoust, said: “It’s clear th…