Update - This issue is now resolved. Thanks for your patience.
Nov 13, 12:28 AEDT

Investigating - "We're seeing a high volume of calls, so getting through to us on the phone or chat might be difficult. However you can still get in contact with us via email (www.amaysim.com.au/help/contact) or there's a lot you can do in our mobile app."
Nov 12, 09:09 AEDT