I can find the same 700MB+ in Creodias - see here!
Considering this is an old product that is being retrieved from the LTA, I would imagine that there is either a problem in the request or in the LTA retrieval side. You can try an alternative source like Creodias, AWS, etc (noting that the data may not be exactly the same) or you can try to obtain support from the official channels of the Copernicus Space Component.
Please note that this forum is about the Software SNAP, it is not a support channel for the generation and dissemination of the Copernicus Sentinel data, for which the above channels exists.
This doesn’t exclude that some member from the community is able to give a reply to the question.