Nothing we can do here, sorry.
There are lots of porting issues currently.
Customer services are the only ones who can help Guide: How to find help & contact O2
I am in the same situation. My port should have taken place on Monday and has still not taken place. Like you though the signal to my old sim ceased.
No luck getting through to customer services though, probably due to the whole Covid-19 debacle.
How long did it take for your old sim to stop working? I'm having the same issue (except O2 to O2) and my old sim hasn't even stopped working yet.
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