You sent too little, deposit has to be at least 20000 satoshi so we can merge the inputs to a large output.
I have sent 0.0002403 BTC, what can I do now? do I lose that money?
In short, yes.
Don't send small transactions in the BTC network, the network fee will take away large portion of your transaction. You should at least send like USD$30 worth of BTC per transaction.
You may have sent 0.0002403, but read carefully the blockchain transaction, only 0.00019 in the output:
32 3AgMgbfFT26Nf1Bc46nRVbTFganhyH12YF
0.00019180 BTC •$5.62
0.00005 had already been consumed by the blockchain network. If we accept your dust deposit, we will pay like 0.0001 to merge it with some other small transactions then send to the seller, if you spent further 0.0001 BTC in dispenser.tf, then your entire value of deposit cannot even cover the network fees for a round trip of BTC transaction from your wallet to the seller's wallet, we will have to pay network fees for you with our own pocket.
