Priority Service

Hi so I applied for a Tier 4 student visa from the USA. When I went to pay for my application on the application site after completing everything there were a couple options the standard visa fee which was like 300 or 400 usd than silver, bronze, services and also priority which was 750. I need my visa soon so I purchased priority and on my application print out there says that I paid for priority service. However after submitting my application I've been reading online that after you make your application you have to purchase priority service via vfs and then include the receipt. But because I paid for priorty at the same time that I paid for my application I didn't go through vfs. And consequently I wasn't sent a receipt to print out for priority. I just got confirmation that I paid the 750. I wrote priority service on my envelope but I'm worried. Has anyone had experience with paying for priority straight up and not going through vfs after?

Thanks!!