Make sure you are inserting it properly in the SIM card holder or it may not make contact with the pins inside the new phone. The tray in my Father's new Moto G30 was fiddly to align the nano card in to snap in place before inserting it
I got my phone from giffgaff but I'm using my 02 sim card. I was receiving calls the day before and I've not changed anything. I've removed the sim card multiple times to double check it's in properly and all my settings are correct via the manual.
Giffgaff do brand new phones and refurbished phones... do you know what type it is? Just to rule it out... have you checked to make sure the IMEI isn't black listed? If it has then you need to contact Giffgaff ASAP.
Strange but at least it's recognising the SIM. If it was network locked to Giffgaff or the SIM wasn't inserted okay it shouldn't get text messages. Have you got a Giffgaff SIM to try in it too just to completely rule out network locking of the phone
Yes I have a giffgaff sim I had to purchase with the phone. I'll try that and see. I contacted giff gaff but they've not got back to me yet. Its just weird that it worked for 24 hours or so now its not working.
I doubt O2 is down in the area... check with local friends n family that their O2 signal is fine...
Sim works in the old phone so a replacement sim shouldn't be needed.
Just checked the Giffgaff site... all their phones are unlocked so any sort of locking issue shouldn't be happening.
If it was me, I'd back up my important data... do a handset hard reset... then see what happens. Cause its a new phone I'm guessing there's not much on it so should be easy to back up or not much data to lose.
If all of this fails... you may need to contact O2 customer support or maybe Giffgaff to arrange a return or swap for a new device.
Even though you've purchased a new phone I would still run it through a black list checker just to see what outcome turns up, some phones have been known to blacklist incorrectly due to wrong information.