Can't leave forced test mode

My S60 watch is since 2 weeks in 'forced test mode'. Every time you've got to go though the entire menu by pressing the top right button but cannot leave this menu. Of course, all hard and soft resets with the middle button and all combinations of buttons have been tried at least 15 times but this is not the solution. Also: latest software update has been installed 3 times, fulley charged the battery, tried empty battery and consulted this forum. Basically, nothing helps and no support is given. 

Please advise since I cannot use the watch at all right now.