On Tuesday (20th August) I needed to travel from Purfleet to Upminster. The TFL Journey Planner gave me the route Purfleet to Grays (C2C) changing to another C2C service to Upminster and quoted £3.10 off peak single. However, on arrival at Grays I found the Subway to be out of use (long term) and the only way to change platforms for the Upminster Train was to tap out, walk via the public footbridge (or over the level crossing) and re-enter the station on the opposite side by tapping back in again - all done within 4 minutes. I have subsequently been charged for 2 separate journeys - £3.40 Purfleet to Grays and £3.10 for Grays to Upminster. Is this correct? If so fair enough but if not then how do I go about challenging it? It seems slightly unfair when I had no choice but to tap out and back in again. (Whilst I am in London a fair bit it is a long way from home territory!)