Swapping to O2: keep number hasn't worked

[HELPMEKEEPMYNO]

I purchased a phone over a week ago, and the next day (19th March) contacted O2 to keep my number. I was on giffgaff pay as you go. I got the PAC code from them and completed the online form.

On Monday 23rd my giffgaff SIM stopped working. My O2 SIM had not swapped over and kept working with its new number. I phoned O2 on this day, and was told it would be 24 hours. It did not happen on the 24th. I phoned O2 again on the 25th. Again I was PROMISED it would be 24 hours. I asked 'what happens if it hasn't worked in 24 hours, what can I do?' the customer service agent simply said 'it will work'.

Alas, it has been over 24 hours, and it has not worked yet. I am completely desperate for my old number to work in my new phone. I am missing important business calls, and messages from family members who are self-isolating and have nobody else to contact. This is urgent and yet I cannot get any help from O2. I am deeply unhappy and need help!!!

[MI5]

@HELPMEKEEPMYNO 

There are system issues at the moment.

I'm afraid you'll need to hang on until it's sorted.

[HELPMEKEEPMYNO]

Not really good enough. 

How do you know this is the case?

Why can't I be told on the phone, rather than repeated told that it will be sorted in 24 hours?

[MI5]

I know because you are one of hundreds who have the same problem on here.
If you used search, you'd see for yourself.