Unexpected call from PlusNet today about my account...

[#1]

...I was at work and someone else took the call, but when I called back this evening they said there was no record on my account of a call being made.
I called Sales to see if it was a promotional call. Nope.
The person definitely said it was PlusNet calling (and the guy had a Yorkshire accent!)
How can I find out what the call was about?
(Not having any issues here, as far as I know, btw. No call was expected.)
No point calling me during the day, I'm not here!

[#2]

Probably a scammer unless you have a fault ticket open

[#3]

Morning IanSn
We do have an outbound team who will contact customers on legacy products to advise of other products however I can't see that they have touched your account. Certainly no one from Plusnet called you. Should they attempt to contact you again, please ask for their name and then contact us once you have the chance. We will be able to check if they work here and if they do, arrange a call back for you with that team at a more suitable time.
All looks fine on your account at present so I can't see why we wouldn't be ringing anyway.
Many thanks
Alex

[#4]

Thanks, Alex
there has been no repeat call.
If we get another call I'll try to make sure to get some more details. Unfortunately I wasn't there.
@Gus
Do hope ppl are not attempting to scam PlusNet! If so, how are they getting our phone numbers?