You should not be charged the £25 change fee...I suspect the agent mis read the date of issue as January 2012 rather than original date of Sept 2011....pre avios t&c will apply. Last fuel surcharge increase was 7 March which would account for the additional £40 per adult...When you do call to amend ensure agent is aware that original date of issue was Sept 2011 and that you are unable to amend online.