You'll find a graph of the incoming call volume here http://www.plus.net/supportpages.html?a=212&helpheader=rhmcallstats pick a quiet time from that.

Hi Tigger,
Sorry to hear about the queue times this morning.
Did you manage to get through in the end? Is there anything that I could take a look at?

Thanks for the link.
Matty, it's something complicated that's had a right mess been made of it at your end. It'd take too long to put it on here. 
And no, not even tried to hang on yet. Message still saying thirty minutes, despite the graph showing something lower. I'll give it another half an hour. But judging from the look of the graph, you need more operators on in the mornings!