Greedy policy
 

COVID 19 is responsible for a lot of changes in quarantine regulation and cancellations of flights.Most airlines do not charge a penalty for changes in issued tickets because of force majeure.
SQ found a trick to bypass this allowance and increase its revenue.If you change your date of your return flight,a new ticket price applies,it is not a penalty for changing the date and therefore you cannot complaint !
You buy a return ticket for $700 and to change your return date because a new quarantine duration applies,the sum of $450 must be paid. If you check the price of a return ticket from your departure city at your return date,it is still $700 and the $450 is for all flights over several months,none is available at the original price.
Trust SQ to find a false reason for this highway robbery.