Strange Voicemail

[#1]

I have just got home from holiday after 10 days and my answerphone had a voicemail message on it from 26th December, which never made much sense. When I dialled 1471 it gave my phone number as the message sender.  Well nobody was at my house those 10 days so how could that have happened.  Also how could I have sent a message to my phone from my phone.

[#2]

HI elkieluca,
Very strange that, never heard of that happening before. In fact, I don't know how it's possible. Have there been anymore problems or was it just a one-off.
Jojo

[#3]

Hi Joanne, thanks for your answer. It was a one- off and I don't understand it either.  The only thing I can think of is ever since leaving TalkTalk earlier this year, they have driven me mad with final bills, that I never owed by the way.
  They sent me a letter a few weeks ago apologising for the nuisance they have been.  But when I got home from my holiday there was another final bill saying I owe over £45 and must pay it immediately.  Well again I really do not owe them anything. So I am beginning to think they are messing around with my phone somehow.
I will now have the inconvenience of having to write to their head office to complain again. What a company!