@jv1999,
I really empathise with you on this. As best you possibly can, try not to think about it. Given that it is a matter of time until you find out, I would wait until the end of this week and if you have not then heard anything, email them to make sure that you have not missed any correspondence from the firm (as they said that they would let you know at the end of last week).
I know these things are easier said than done though. Just remember that following up will not make a tangible difference to the outcome.
On a slightly different note: if you do hear positive news, please do ask if you are unsure about anything! W&C were one of the firms I completed a vac scheme with and I would be more than happy to help!