I have used them a few times the usually deliver within a week, but my last order took 3 weeks. I will use them again.
It does say on the site
UK NORMAL DISPATCH - £3.95 - 1-3 WORKING DAYS FOR DISPATCH ITEMS ARE SENT BY 1ST CLASS ROYAL MAIL
PLESAE NOTE: The DISPATCH time is when the item will leave our warehouse
Your goods are dispatched by 1st Class Royal Mail as our dispatch team come to the order.
Delivery usually takes 3-5 working days AFTER DISPATCH via 1st Class Royal Mail Post
And
Despite our best efforts, there can sometimes be unforeseen delays in delivery. It may be worthwhile contacting your local postal sorting office as they may have tried to deliver your package, but were unable to. Should you have not received your full order within 28 days of DISPATCH then please click here to report it. Written, signed confirmation of non-delivery may be required.