Someone "streaming" on my router yesterday and today

[EmNetta]

Although Plusnet helped me change password and this month's billing ends tomorrow, I'd like to find out who's been doing this, and how. Any ideas please ?

Thanks again, Network Guy, I'm really grateful for such expert help, and will print off latest for reference.

Just had opportunity to ask family member about Hudl, and it does indeed use wireless. (Probably the whole world knows this but me . My printer, on the other hand, defied combined efforts of helpful friend and (expensive) professional to install wirelessly, so I've been told I don't have to find yet another password.
Off now to sort out altering excess charge on account, thanks again to NetworkGuy, it is a good idea.