I am trying to save a message which will be guided by ampscript for a single opt-in message. Am I doing something wrong?

%%[ SET @Row = LookupOrderedRows("SMSData_FromWeb_ToMC_Test",1,"DateTime Desc","MobileNumber",Mobile) SET @Card = Field(@Row,'CardNum') SET @FirstName = Field(@Row,'FirstName') SET @LastName = Field(@Row,'LastName') IF RowCount(@Row) > 0 THEN SET @Message = Concat('Thanks for subscribing ',@FirstName,' your Card Number is: ',@Card,' -- You'll get 4 msgs/Month. Rpl HELP for help. Rpl STOP to cancel. Msg&data rates may apply.') ELSE SET @Message = Concat('We're having trouble processing your request') ENDIF]%%
%%=v(@Message)=%%