Santander website and phones

[pizzaeatingmonkey]

My pc crashed and wiped all my saved details so today I've been trying to get into my 123 account, but I cannot find my customer number.
I've followed all the links and filled in my name, address, DOB etc. but it doesn't recognise it and keeps asking me to check and re enter. I've even got DP to double check I'm not making silly mistakes, but no...I do know my name etc.
I've tried to phone their usual number but they are 'experiencing a heavy volume of calls', and I need to put in my long number off my debit card (which I've never used) which I've now discovered is 4 months out of date.
I've gone through their FAQs and found another phone number but that just goes dead!
Has anyone had the same problem? Is it a fault at their end? Can someone help please?
(My first ever post and a very disappointing one).

Take some ID with you and go to your local branch, they should be able to help in some way.

The long number should still work even if the card itself is now out of date. Have you tried it? Have you also tried a different browser? Chrome is not always well supported.

You could also tweet and ask them if there's a problem at their end.

Gosh, thank you for your comments tribpot and Mayhem.
I'm not able to get to the branch until next Monday ( I live in the sticks) and I did try the number 3 times before realising that the card was out of date.
I have got a twitter account....well I did before my pc went berzerk ...I've never tweeted though [goes off to find Twitter].

I found Twitter and did my first tweet to Santander, do I have to follow them to receive an answer? .

Nope! When they reply you will get a notification (if you have Twitter installed on your phone) or you'll be able to see when you go back to the website that the little bell symbol at the top will have a 1 next to it.

If they reply this way, it will be a public message so if they need anything identifying from you (shouldn't do really as you just want to know what phone number is best to call) they may ask you to follow them so they can send you a private message. It is now possible to send private messages to people who don't follow you, but I would suggest turning that off at once (it should be off by default). You can check under Settings --> Security and Privacy, it's down at the bottom. To get to settings on the website, click on your profile picture to the right of the search box.

Their number is 08009123123 - each time I call I get that message but usually get through in just a couple of mins

All sorted and they were very helpful ( as you have all been ).
They e-mailed me within a couple of minutes and it's all sorted out now, what a relief!