Patience is a virtue. Anyway it's too cold to fit the stick on Velcro tape (as per the instructions) at present.
I am certain that when the shop receives them you will get your Isotop immediately. In my experience, very few suppliers are as quick and efficient as the club shop in processing and delivering items. Of all of the items that I have ordered from them and there have been plenty, they are very quick to Email you at every stage of the ordering and despatch process and the well packaged items have turned up either the next day or the day after. So I'm sure the problem is outside of their control.
I don't know what Brandrup's terms of business are but they may have insisted that orders are paid for up front especially at the current time. The Isotop is a high value item and personally I don't think it unreasonable for a small company to ask for payment for a customer's order in advance. The other thing to bear in mind is that they may only get a few in the next Brandrup delivery so having already placed an order and paid for it should ensure that you receive one of those. I tried to order one for our new Beach a few weeks ago only to be told they were out of stock. Whilst I didn't order at that point, I did immediately they were back in stock and I managed to get the last one they had!