Changing Economy Comfort seat selection on Delta flights

[Avidflyer]

Sorry if I have posted this question in the wrong section.
My question is ..
I have purchased an Economy Comfort upgrade seat on a Delta SYD-LAX flight for next month.
When I booked, i wasn't able to select an isle seat, now when I looked last night,
There are several available!
I attempted to re-select online, but a msg was displayed that purchased upgrades are not re fundable,
So I cancelled this.
Is there any way I can select an isle seat without loosing my paid upgrade?
I'm currently booked on a Delta ticket.
Thanks in anticipation

 

[serfty]

Is the aisle seat an "Economy Comfort" seat?

 

[Avidflyer]

Sertfy,
The seating set up is 3 x 3 x 3
Currently allocated 22E
Yes the other isle seats are indicated as EC,
But when I attempted to change seats,
A pop up window stated that purchased EC were not refundable, and I didn't want to loose my $,
So I wasn't game to proceed any further, and posted here for advice

Thanks

 

[serfty]

It's a long flight to be in a middle - I would have though any amount already paid would be used to offset in such a case.

What happens if you take it through to the part when it asks for additional payment (if any)? I suspect you would still be able to back out without losing your 22E at that point.

 

[Avidflyer]

As they say..
You snooze, you loose.. All the isle seats now appear to have been booked. ;-(