Dual SIM problems abroad

[Josie64]

Two weeks ago I purchased a rolling plan sim. I had my number ported over as this was to be my main number.  For some reason this took 5 days to happen.  The sim worked for a day, but reception wasn't great.  As my phone has dual SIM capacity I also purchased a PAYG SIM from EE as a backup.  I inserted that the evening before travelling to France for a two week holiday.  Arriving in France my O2 SIM doesn't work and it doesn't have a tel no associated with it.  I can't contact O2.  My EE SIM works fine.  However, when I send a text it may say sent from O2.  If I switch off the O2 SIM neither SIM works.  I've tried switching over which SIM is in which tray, and removing the EE SIM, but neither works.  I have another week in France with no ability to use my every day number.  Any ideas?

[MI5]

@Josie64 

You can choose which sim you want to use for calls, texts and data in your phone settings.

As your O2 sim appears to be offline, you will need to contact O2 by any of the methods here Guide: How to find help & contact O2