£250 to elevate your brand with Sponsored Brands

So I got the following email from Amazon in October:

Hi,We’re offering you £250 in credits to experience the potential of Sponsored Display. Just create and launch a Sponsored Display campaign by 11/01/2024 and the funds will be added to your account.*Terms and Conditions apply. This offer is eligible for Amazon.co.uk.

OK. Seemed simple. My margins are pretty tight so I wouldn't dream of throwing this sort of money at an advertising campaign but who doesn't like a freebie? Launched the campaign on the 29th October and BOOM! It ate through the promotional budget in no time regardless of how I tried to contain the clicks.

Anyway in four days it is up to £210 and to be fair, the results have not been great. My concern is that I have had no correspondence from Amazon in relation to launching the promotion and I can't see a credit has been applied anywhere on my dashboard. Now I am seriously concerned that I have missed something. Amazon have already taken a payment for these days today. I simply can't afford this. Any help would be appreciated.