There are 2 things to consider here:
1. Under current rules no call can last for more than £30 at any one time. This means that if you were to operate a premium rate number charged at £1.50/min – the maximum duration of the call would be 20 minutes before you had to end the call.
So for a call to last 2 hours – you could only do this by operating on a premium rate tariff where the call cost is no more than 25 pence per minute.
2. If the person who made the call to you did not have permission to use the phone they were dialling from – then the owner of the phone bill can apply to phonepayplus to organise a full refund. This means you won’t get paid.
However, if the call was genuine and someone is just refusing to pay their phone bill – then you will be paid.