is it mobile or landline? My mum got numbers she hadn't dialled on her lndline, they were long calls to India. She contacted BT and they took them off her bill
00 does indeed put you into the international network from the UK, however 08 is an invalid country code.
It looks like it makes no sense to me. If it were shown as a caller identity I'd say it was spoofed, but if you have been calling it, getting through to somewhere, and being charged the Earth, then that's a mystery. As is why anyone would want to dial a number they didn't know in the first place.
If you have been charged for these numbers as though you dialled them, and they are on your itemised bill, then get in touch with your service provider
( whoever you pay your line rental to ) and ask them to confirm the number.
I must add,( but it is rare,) that BT staff when working in a joint or a cab, can cut down a pair of wires and clip their phone onto it and use it, and this does still sometimes happen, so then people get strange numbers on their telephone bill.
My mobile phone had used up all its credit (almost) although I had not used it. My brother discovered that 0740 73210501 and 0740 7321950 were the last two dialled numbers neither of which mean anything to me.
craft,
Most people working on BT plant are now contractors, not proper employed BT staff, they come in through agencies, and are on very short term contracts,
poorly paid, and they really are not the staff of 20 years ago.