In the case of ethereum -address substitution detecting, which is used for top up F-purse, immediatly contact with technical support.
Carefully check the address displayed on the page and then performing copy and paste operations.
Do not transfer funds if you are not sure that the address is correct!!!
See also:Substitution of the bitcoin purse's addressSubstitution of the litecoin purse's addressSubstitution of the bitcoincash purse's address