Phone line fault - plusnet inactivity for 6 days and fraudulent activity

[#1]

I reported a fault with my phone line (noisy line) last Wednesday (11 November) using the online chat thing, and have not heard anything until today whether or not this would be investigated. I told plusnet on the 11th that I would be available for an engineer visit today (17th).
I have received a communication from plusnet  today that claims that I have spoken with them via telephone (today) and that I have agreed for an engineer visit this Thursday (19th November). I HAVE NOT SPOKEN WITH ANYONE ON THE TELEPHONE TODAY LET ALONE AGREED TO AN ENGINEER VISIT ON THE 19TH.
Claiming that they have spoken to me on the telephone today to agree an engineer visit is a downright LIE.
If I am threatened with the £50 charge to re-book the engineer then this will escalate into a very serious matter.

[#2]

Hi mitmit
Sorry to hear this.
I would guess the appointment was booked for the 19th if the 17th wasn't available.
Apologies for the update on the ticket, I took this up with the agent involved who was working on tickets and not calls yesterday, they were booking the soonest available appointment and failed to correctly update a pre-written respone which includes the line "Thank you for your time on the phone today." I've given them some feedback on this and to make sure they check and update such responses or even better avoid using them.
I'm glad to see you've since spoken to us and we've arranged another appointment that's convenient for you.