"In spite of several reminders,he DID not so far send any reply to my letters."-Wrong sentence "In spite of several reminders,he HAS not so far send any reply to my letters."-Right Sentence.

Why do we use has in this sentence but not did????

In spite of several reminders, he did not so far send any reply to my letters.

The above sentence is incorrect whereas the correct version is:

In spite of several reminders, he has not so far send any reply to my letters."

Why do we use has but not did in this sentence?