Same here, one which was expiring June 21 now been pushed out to Dec 21. Nice.
Though mine was earnt December 2018, for 2 years. Extended 6 months to June 21 and now again to Dec 21 (so now 3 years)
How is yours 3.5 years I wonder?
Glad i left mine in anticipation of this rather than doing the FTV trick.
They did another extension in Sep/Oct/Nov time for vouchers expiring in the 6 months from that point, moving mine from 2.5 to 3 years, then the further one today made is 3.5