seller not communicating

[streetch]

I won two items from the same seller - I didn't realise until after the bidding ended that it was the same seller so I messaged straight after I won asking if they would combine postage. The seller replied straightaway saying no problem and I thanked them and said if they sent a new invoice I would pay immediately. Since then there has been no response . I was getting lots of payment reminders from ebay so I paid for one of the things 3 days ago and sent another polite message to the seller saying again that I would pay for the other one as soon I received the revised invoice but they have not replied and I don't know what to do now. It's been a week since the auction ended and I'm pissed off at the lack of communication! Can someone please advise me on timescales on when to open a not received case or if there's a way to message ebay to get them to give the seller a prod?

There's no point messaging eBay and asking them to contact the seller, they won't.

Personally what I would do is, pay for the second item now. You can't force a seller to combine postage. (I know they originally said they would, but that's a red herring at the moment.) , then if one / both don't arrive, open a not received case (you can do this from the last date of the delivery estimate provided when you pay).

If they both arrive and have been sent in a single package, message the seller and ask them to return the excess postage, as previously agreed.
If you don't get it refunded, then leave factual feedback detailing this.

That's all you can really do IMO.