Thank you for taking the time to get back to us, you are speaking with Jem as Matthew is not in the office today.
I am very sorry to hear about the problems you are having. I completely understand how important it is to be able to stay in contact with people, so this must be really inconvenient for you.
I have checked your account, and everything appears to be okay from our end and I can also see that you £10 goodybag is still in place and is active. As the previous adviser mentioned it does seem to be on Plusnet side as they are the only network who can not call you but we would advise you to try all the steps advised bt Matthew to see if it helps.
If none of the steps resolves or identifies the cause of your issue, this would suggest that the problem may be being caused by your SIM card, and so the next step will be to do a SIM swap to replace the SIM. You can find out how to do this in this handy guide: http://community.giffgaff.com/t5/Using-giffgaff/What-is-SIM-Swap/ta-p/7320084
If your services still are not working 24 hours after activating the replacement SIM and completing all the other steps too, let me know and we will investigate further as we want to be sure that your phone is working completely again.