Apple Pay DECLINED

I've been using Apple Pay for ages. In fact all the time. Every transaction has been a breeze until now.

Today, I have been declined twice. Once for a purchase at a retailer for about £200 and at my local (thankfully) petrol station.

Luckily at the store, I had the debit card linked to apple pay, which when used with pin-pad was fine.

Unluckily, at the petrol station, I had to drive home and return to pay again.

Who is responsible for declining the transactions? Is it Apple pay or The Bank?

It's really frustrating when something designed to improve and simplify your world, frustrates and annoys.