Your sentence is incorrect. The word neither already negates the second part of the sentence, so haven't should not be negated again and should instead be have. Also, you should use nor instead of neither:
You haven't sent me the file nor have you told me why I should make another technology request.
You can use neither to negate the first part of the sentence:
Neither have you sent me the file nor have you told me why I should make another technology request.
When the first phrase is negated, nor can be used to negate the second one as well, but neither cannot be used for that. So the correct construction is a negative phrase with not or neither followed by a phrase negated through nor.
- Neither...nor...
- Not... nor...
In short answers you'll often see neither:
- I haven't seen him.
- Neither have I.
But in such sentences you could also use nor:
- I haven't seen him.
- Nor have I.