Hi Colin,
There’s no way to get the PAYG fare without using Oyster or contactless. You would only need to touch out at Enfield because the 60+ Oyster is effectively an off-peak season ticket so it doesn’t matter if it’s not touched in. Changing at Cheshunt and using London Overground is really the only sensible way, and it’s only £2.20 off-peak.
Re the trip you made. If you call the helpdesk they should be able to sort it out, but they won’t want you to make a habit of it.
