My phone and my wife's both had good signal but failed to make calls all afternoon. I was in the Harrow area and my wife in west central London. Both phones gave a Network Busy and engaged tone for every call made from 11am through till after 5:30pm. We had to resort to landlines and email - not impressed. I turned off, removed the sim (the usual) and tried phoning many times throughout this time - even calling landlines got the busy signal. Calls to the mobiles from landlines failed thoughout this time too. When trying things after 7pm, all was well again. Note, I tried contacting O2 customer services with a landline about 6 times over this period - always to get an engaged tone. Our contract has just expired so this is one issue I'll happily resolve with a move.
