I was averaging 2 weeks to get my full repeat prescription (18 items) last year with my previous chemist. I since changed to Boots and never had a problem with my full script ready in around 3-5 days after putting in.
The one item I do struggle with, which not on my repeat as I have to phone to order more about every 3 months is Hydrocortisone sodium phosphate injection (addisons disease), as its out of stock at the manufacturers!