Transfers from funding sources ie bank account or cards are never instant, that is why when you buy something paypal credit the seller upfront for you and paypal take the wait for the funds to transfer to pay them back again, this is so you get your item without delay.
Takes several working days to transfer as Paypal use the slowest (cheapest) transfer option BUT funds normally leave your bank account from a few hours up to a few days later. With cards its normally within 24 hours.
Advice is voluntary. Kudos / Solution appreciated.
Do you know if they have policies on maximum time that can pass before a payment is then not valid. I have experienced an extremely long wait before the payment was finally taken. It did appear on my bank statement for first couple of days after completing original transaction, but then got lost from sight in liat of transactions.
