Translation Results Requested Through Conyac Made Public

I'd like to ask you refund for the following Script .

The reason is as follows:

The more posts, the more lagging when displaying them.
※ There are many other users who have the same problem.

Part of it may be a problem with WP, but most of it is caused by this Theme itself.
According to the support bulletin board, one fundamental solution seems to be to rent a best-fitted server.
I tried a cache-type plug-in, but there was no improvement.

This problem would not appear unless quite a many number of articles were posted.
At least, nobody can expect such a problem before the purchase.