First, on the off chance that you are Robert Wemischner, editor Brad Wilber is looking for you as his emails are bouncing.
If not, here's my suggestion. I'd hang in there and wait it out. Some editors can be really slow in responding and occasionally exceed their "target" response date. Since you're a new contributor, it would not be looked upon favorably to withdraw a submission before getting a response (unless there was another reason besides the length of time involved). The fact of the matter is that it "comes with the territory" with certain publishers that you have to wait a long time for a response.
Assuming you're not planning for your constructing career to be comprised of only one puzzle, I'd get to work on more of them. If you're interested in a quicker turnaround you might consider trying one of the publishers who accept theme queries - these usually respond faster than those who require a completed puzzle for submission. In any case, it's very typical for constructors to have several puzzles pending review while other puzzles are in various stages of construction (I have about 20 awaiting response at the moment).
I'd also suggest you try reaching out to other constructors for comments about your work to make sure it's in good form and also for suggestions about which publisher(s) might be more likely to be interested in a particular type of puzzle. A great place to make contact with them (besides this forum) is the Facebook group Crossword Puzzle Collaboration Directory.
