Swapping Sim - O2 have both numbers active

[JD13]

I gave my dad my old iPhone, but he needed a nano sim so we did a sim swap and the old number now works on the new sim, but O2 have emailed to say the following:

After revalidating your request we've identified that your request has
been booked into incorrect queue.

As both the keep and temporary numbers are active on same billing
system.

Kindly contact O2 front-line advisor and ask them to fill up a correct
form for you.

I can’t find anywhere to contact anyone, how can I sort this out please?

[MI5 · Accepted solution]

@JD13 

You'll need to call customer service.
Numbers here Guide: Coronavirus Community Help and Support 
When it comes to the reason you are calling stay silent for 15 seconds and you will be taken to the keypad options.
Press 2 for Everything Else
Press 5 for More Options
Press 7 for Anything Else which will put you though to someone.
Say "Upgrade", "Lost/Stolen" or "Fraud" if you have to, to get put through to someone.
8.00am is the best time to call if you can.