Great question — answering as the UphillTech team:
Kiwi's operating model generates a lot of risk for its customers and as a result is full of customer complaints (as already mentioned in the comments). Unfortunately, I doubt you will get the flights from them. However, you might still be able to recover your money. If you paid with credit card you could make a chargeback request arguing the agency is not providing the service you paid for (the four flights). I have been in a similar situation with them and I made a chargeback request successfully. It is also important to first request a full refund directly from Kiwi and only start the chargeback in case they refuse your request.
Full answer by André: https://travel.stackexchange.com/a/190249 (CC BY-SA 4.0).
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