O2

Do these minutes include calls to international mobiles or are they for landline calls only?

I currently get a £10 Big Bundle each month. O2 keep asking me to change to being on contract. I presume that if I change in the middle of a month, then I would not get credit for the unexpired portion of the Big Bundle. Is this correct?

If you have a credit balance, is there a way to stop a big bundle being renewed and go onto standard PAYG rates?

I have a large credit balance on my PAYG account. If I transferred to pay monthly, can this credit balance be used to make the monthly payments? If not, in which circumstances would the credit balance be used rather than taking money from my bank acc...