Incorrect bill

[Hannah226]

My bill was significantly higher this month but I can't work out why. I recently swapped my phone but the credit agreement was paid off . 
I had to pay £12 up front and then my monthly bill for the phone is £25 however I've been charged £48

[Daniel0210]

@Hannah226 

Check the dates the bill covers; is it longer than the normal month? Compare it to a previous bill to see where if differs.

An increase normally means roaming charges, buying some extra data at £6.00 per GB, sending chargeable picture messages (95p each), calls to non-inclusive numbers or a discount ending.

Only 01, 02, 03 and UK 07 mobile numbers are inclusive.

[PandJ2020]

The bill will be fully itemised.  It's possible another payment for the swap phone was collected?