Call charges for calls i didnt make

[#1]

Unexpected larger bill this month with approximately £16 worth of calls to 123 and random numbers. Calls are very short and most are zero seconds! Plusnet live chat assumed that the problem was with me and that something on my phone line had been making the calls. However, other than my plusnet router there is nothing attached (not even a phone). Line tests are coming back normal and engineer has been booked to come out. The threat of £65 engineer call out charge is rather alarming.   

This does appear to be a duplicate of https://community.plus.net/t5/My-Account-Billing/Charges-for-calls-I-didn-t-make-including-123/m-p/1... .

Can anyone help?

[#2]

My guess is that the 'something on your line' is an Openreach engineer. I hope that a Plusnet staffer picks this up soon as I doubt that an Engineer call out is justified at this time. Repeated calls to the speaking clock just aren't random occurrences caused by a faulty line.

[#3]

Hi there, 

I think an engineer visit would be a good idea to investigate the origin of the calls but I'll make sure you're not charged.