I’m afraid this sort of thing happens. I don’t use Curve for large amounts because its happened to me and I’ve seen it happen to others.
You will likely get it sorted, but I can appreciate that 2k missing is not pleasant. Its just possible it will all come out in the wash without any intervention, but I wouldn’t wait around for that to happen. Unfortunately all that anyone here can do is advise you to keep pressing Curve to take action - be polite, but firm and know your rights.
If it doesn’t resolve itself promptly…
Its worth speaking to Barclay card - tell them the Barclaycard-Curve transaction was authorised by you but Curve have not reflected the e-money purchase by completing the rest of the transaction. This is essentially the same situation as ordering something online but the seller never putting it in the post.
Explain that Curve are not responding to your requests for assistance, and try to pin them down on at what point (how many days / attempts / media you should try) they will consider Curve’s non-communication to be something they will investigate - ie Barclaycard will take action on your behalf.
A moderator - they have no particular power, don’t worry - may threaten you with legal action from Curve for doing this, but please don’t listen. You are simply asking your card provider to assist you in investigating why Curve have taken your funds but not passed them on as you instructed them to. You are entirely within your rights and Curve may be more willing to talk to Barclays than they are to one of their own customers.
And finally, if Curve do chose to engage to you - make sure sort it out and refund you any interest you’ve been charged due to the delay, plus some sort of compensation for your trouble in chasing all this down. A promise to take your complaint to the Financial Ombudsman service usually gets the Curve cash flowing.