Unwanted Text Messages On Bt Landline Phone

[Coppit]

I get regular twin messages quoting 86444 and a menu of options including one to stop these calls, but I'm suspicious of that. Can anyone shed light on what this may be about and presumably I'm not being charged by BT for these calls which appear to be regular recorded phone messages.
I joined Twitter a few weeks ago and have never used the service. Any connection?

[Jomlett]

It could be from twitter....Both Sky and Bt say: to stop these texts...

1. Call 0800 587 5252 from your landline number (it's a free call).
2. Listen to the interactive voice menu and select option 1.
3. Listen to the next interactive voice menu and select option 5.

[hc4361]

Check your twitter settings - have you enabled mobile notifications on any of the accounts you follow?