Red-Terror said:
Someone (only one player or an entire combine) has filled with a lot of units (by sending them in reinforcement) a free depot.
The enemy units you see in the report are only those that you have destroyed with your offensive forces ... not the total amount of units that were present inside the depot.
It's a trap (free depots attract players) ... and you've fallen into it.
I would say he was looking for a game mechanics answer to explain why the loss ratio was so off.
The answer is that you were on the receiving end of siege mechanics (see the second point here: https://plarium.com/forum/en/soldiers-inc/game-tutorials/39722_a-summary-tutorial---finer-points/). What this means is, in this situation your offense was heavily outmatched. Because siege mechanics work through overwhelming force, as one side becomes much stronger instead of having 1:1 losses slowly the stronger side's loss ratio begin decreasing.
Note that siege mechanics do not apply to all hits, for example raids are still 1:1 after accounting for bonuses (such as base defense). However, mining complexes, depots, repositories, occupations, and combine HQs are all siege based.
As an aside, note that the server takes a VERY long time to update when people have taken over something. This usually ends up requiring a refresh to see properly, although Red-Terror is right that some people also send defense to them in the hopes someone will try to attack it.