Your own WiFi comes from your own broadband connection, so it counts against your usage.
If you had connected to the BT FON, or BT wifi signal coming from your own home hub, it would not have counted, but you would have run out of minutes, as its not unlimited.
You are are not charged for the first time it happens, only if you go over the limit next month, so at least you now know where you stand.
if the customer services would of told me what you have confirmed I would not have taken broadband with bt . it was they that told me it was unlimited...
If you end up getting near your limit this month, then just use your BT FON/BT wifi connection.
There is a guide to broadband usage here.
If you really want to make full use of your BT Broadband connection, then upgrading to the unlimited package would make a lot of sense.
Just keep a watch on your usage this month.
If you would like to try Live Chat they should be able to help you with that information.
If not, then,
If you would like to contact one of the UK based BT Care Team who moderate this forum, they should be able to help you.
They can be contacted using this link BT Care Team
They normally respond by phone or e-mail, within three working days, however you should get an immediate confirmation, with a tracking number.
that's the other thing though , they never sent me welcome pack with information on what my password is.
Did your home hub not come in a box with, among other things, a slip of paper bearing the default SSID and password?