Thanks for your feedback. You should have not paid anything further if you parked between the times on your booking as you had prepaid. You will be entitled to get a refund from the airport for this. Please contact them quoting your booking reference from ourselves to get this sorted.
“Arrived in the early hours of the morning and plenty of parking available. Drove up to barriers where registration recognition technology was used to allow access with ease.
Parking is across the road from the airport and reasonably priced.”