You will have a label and you won't be able to pay the extra.
Personally, I would take the parcel to the Post Office (or the courier you have chosen) and pay to send it.
Then, claim the cost of the Simple Delivery label back from Ebay.
The tracking shown will be for the Simple Delivery label so will not show as delivered.
So, you can either wait for payment (14 days after the transaction) or contact Ebay Customer Services and ask them to change the tracking.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)