Help Assistant: why does my mobile phone number keep getting rejected?

[#1]

I am trying to send a support ticket as I have a query. Each time I try it keeps regurgitating the same error: Please enter a valid mobile phone number.
I have tried with the following:
Conventional UK format: 07xxxxxxxxx (11 digits in all)
International: +447xxxxxxxx
International: 00447xxxxxxxxxxx
And even unchecking the tick box: Receive updates via text message to: 07xxxxxxxxxx
It still prevents me from sending the support ticket, even if I don't request that it updates me via the mobile. I am a recent convert (from TalkTalk) and am getting increasingly frustrated at not being able to ask a question (which, regarding a potential switch to Fibre. hasn't been answered properly on this forum so far).
Can anyone please advise or assist?

[#2]

Hmm,
I'm not sure why you're getting that particular error.
Are you seeing no options for a chat?
Also feel free to PM or reply with your query.
Adam

[#3]

Thanks Adam. Just to clarify the error message is given in a dialogue box shown in Google Chrome - see attached.
The question I was trying to post was:
Hi,
I have recently switched my broadband (only) to Plusnet from TalkTalk, due to the inefficiency of their mail system. I am very pleased with the service from Plusnet - so far - but have hit a problem.
I wish to move to a Fibre connection (17Mb) but have been told I need to pay yet another activation fee of £25. As I only switched three weeks ago (but have been trying to find an answer for over a week!) it seems very unfair to impose yet another activation when I could have gone straight to Fibre in the first place.
I would switch my phone as well, but Plusnet is unable to match TalkTalk's unlimited phone calls to International destinations of up to to one hour at any time, and I estimate I make up to 20 hours worth of calls per month to the continent. I am also worried about losing my memorable phone number, which TalkTalk cannot guarantee.
So is it possible, to a new and unknowledgeable customer, to offer me the switch to Fibre without any activation fee?
With thanks

[#4]

I suggest that you get rid of your email address in the image

[#5]

Yes, I noticed it just before your post!

[#6]

Looking at the smudged out image it looks like your number starts 074 ...but aren't these premium rate codes ??????

[#7]

No, it's a Three mobile phone number - Pay as you Go 
http://www.ukphoneinfo.com/07449-numbers

[#8]

Yeah, it looks as though 074* isn't a recognised number format, that's something I can look at, but not something I can fix straight away.
http://forums.digitalspy.co.uk/showthread.php?t=1167705 - Looking here, it appears that 074 numbers were allocated in 2009. I'll follow this up.
Apologies for the inconvenience this causes you in the meantime.

[#9]

OK, thanks Chris. I am surprised that no-one else has picked this up before, though.
In the meantime, is there anyone who can help me with switching to Fibre without having to pay another activation fee?

[#10]

I'd recommend calling the customer options team on 0800 013 2632 to discuss this.

[#11]

I had already tried that, of course, but feel that waiting "due to high call demand" is not clever when I just want a simple yes or no. Hence the need to raise a support ticket, but unfortunately not with my mobile number, despite being issued 6 years ago.

[#12]

Typically, with a broadband only account, the answer would be a no. However, I cannot vouch for what our Customer Options team can offer as a retention, which is why it may be your best bet.
Matty

[#13]

And so I phone and wait 13 minutes only to be told the line is "crackly" and the operator can't hear me, no matter how clearly I speak. Well, I was using Skype, so why the "crackly" line?!  - My microphone is fine and I did test it. Last night I tried only to be told (when the line obviously wasn't crackling) to redial for Customer Options, who had packed up and left at 8:00pm.
I can't send a support ticket because my mobile number format isn't recognised - but why is my number required, and why should the omission of that prevent a support ticket being sent? An email reply will do me fine. So could a Plusnet operator please just send message #3 on this thread to Customer Options on my behalf?

[#14]

And now it's a 30 minute wait.

[#15]

If it just needs a valid number that won't be used, couldn't you just enter any other mobile number (friend, relative)?