AIS THDDNS Capcha Not Working?

Have been trying to access my THDDNS account but it rejects the Capcha code every time.  The other details on the form are 100% correct.  It worked fine a couple of days ago.  I'm overseas and can't find a suitable phone number or other way to report the problem which seems to affect different OS's and hardware, so:

Has anyone else had the same issue and found a way round it?

Would someone kindly alert AIS Fibre to the issue

With thanks in advance