Although the Avro web site gives all appearances of being broken it still works if you persevere.
I've just been able to download my previous statements etc. and print off other relevant details.
It took around 5 attempts on each screen but even when it comes up with an error message just hit the button again or just wait 5 minutes. On some pages the response is very delayed whereas the pop up error message so fast :)
I assume a fair number of Avros 580,000 customers are trying to do the same as I, and all at the same time. :(