I tried cancelling online, and got a voucher. Avios did not go back to my account.
I assume the voucher includes the Avois and tax.
is there an easy way to change avios reward ticket online? There is no option to do it, so I ended cancelling.

now that I have a voucher, what’s the best number to call to rebook. I was given the run around. Tried 3 numbers.

1 (877) 767-7970
+1 (800) 247-9297
1 (800) 452-1201