Error in bill and how to contact plusnet support

[#1]

My SIM only bill is always £7 per month.

Next month it's going to be £21.46!

Im a UK customer on holiday in Australia and needed to make a reverse charge call to my insurance company before I could get emergency dental treatment. I believed I was making a reverse charge call and as you can see I'm about to be charged £14.46 extra through no fault of my own ! I want to contact plusnet and ask if they can cancel this extra charge.

There's no way I can email them or contact them in any way as calling 500 will incur extra charges. Has anyone got an email address for support please? 

[#2]

@ruxton28 

Calls in Australia cost £1.45 a minute. Did it take 10 mins to set up the reverse charge call or was this your total time on the call?

[#3]

It took three calls in all. The first two were to customer service numbers which weren't manbed over Christmas and the third was answered. The insurance company insisted that you get permission to get treatment before proceeding. I had a bad toothache and so I had to get it sorted so I persevered. They don't give a method to reverse charge call on a mobile phone despite me asking. They don't indicate that they will reimburse me either, for something out of my control. I'm hoping that plusnet will squash the charge. Does plusnet read this forum?
Also can you please advise how I can contact plusnet from Australia? I can't find an email address and if I tried to call 500 from my phone I'm currently outside of the EU and will be highly charged again. Plusnet should provide an email address and a live chat for customers like me who cant contact them and are in need of help

[#4]

Plusnet staff do man these forums but can take time to reply.

[#5]

According to this - "... there is an email address for mobile queries and that’s mobile-help@plus.net ..."

EDIT

It is also shown on the https://www.plus.net/contact-us/ link, choose "Make a complaint" on the left, then "I'd like to make a complaint" in the centre, and it becomes visible on the right hand side!