"Rude, careless and ill informed receptionist"

Went for a simple skin concern as it is 5 min walking from my work place, explained to the receptionist I am not currently registered with a GP. First thing I was asked is to pay 75GBP because they cannot recover the cost to my doctor? Even having a national insurance number? Insisted they would need a payslip so I could get refunded. Again, necessary when having a health insurance number? And on top of that, given attitude like I have never experienced. Eventually, I was not even seen by the nurse as they had closed the waiting list for the day and was told this only after being questioned for not having a doctor!