Can't make calls, just says bundle call

[What2]

I just topped up but when I try to make a call it just says "bundle call" and terminates the call. I have used this number to make calls in the past and have never had this problem before

[MI5]

@What2 

We’re just customers like you but it sounds like you’ll need someone to access your account which can’t be done from here. If you message O2 on Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) , they should be able to help you with this
Thanks

Guide: How to find help & contact O2 

[Oxonian]

What happens @What2 if you try to 'phone another number ? Or if you try to 'phone the number that you are ringing using a borrowed 'phone ?

I am on a PAYG Big Bundle and every inclusive call has an oral message that says "Bundle call" before it goes on to ring the personal that I am calling. 

The fact that you are getting the "Bundle call" message suggests that your bundle is active, so I am wondering if you have a network signal, handset or SIM issue ?