Can't withdraw a nomination still in queue

There is a brand new mural in my local area, and I submitted it on 9th April, and it's still in the queue so I clicked 'upgrade next' last week when my other upgrade was applied (and accepted)...
Today I see the mural is now a brand new Pokestop so someone else must have submitted it too...
Now my question is this - I tried to withdraw my submission thinking it should be ok as it's not in voting and the upgrade still hasn't been applied but it's telling me "unable to withdraw the submission"
Is there a way to get my upgrade back? As this just means it will be a wasted one, come back as 'duplicate' and I will have to review even more to get another upgrade ... I am an active reviewer but not too active (good rating / 13 upgrades redeemed so far) and this is slightly annoying and will mean taking longer to get other things upgraded (as in my area things stay in voting for months - I have things from last year still in voting)
Thanks
Comments
You cannot withdraw a nomination that is selected as “Upgrade Next”, unfortunately you will have to wait for the Upgrade to apply and then I believe you can withdraw it. I don’t think you will get the Upgrade back though.
Thanks. I guess I will need to be less 'trigger happy' with my upgrade next and wait until I'm nearly there before applying the upgrade.
Thanks for answering