I hate to say this, but the manufacturer of those ribbons has a very high rate of initial defects. The problem is generally caused by the ribbon corrugations (folds) straightening out, and given how much protection that mic has around its ribbon, unless you pointed an air compressor at it, I doubt you caused the damage. If it isn't too late to send it back as defective and get a replacement, I would suggest that you do so.
If not, see if the 1 year limited warranty will cover a slack ribbon. Apex covers theirs, but most of the Chinese ribbon mic resellers don't, probably because they would have such a high return rate if they did. If the warranty doesn't cover it, find out what it would cost for an out-of-warranty repair, but be prepared to not like what you hear....
Having somebody else repair it is probably out of the question. The cheapest third-party reribboning services I've seen are from ShinyBox ($120) and OktavaMod ($125). Since you could replace the mic for $99, that might not make a lot of sense, though admittedly you could be fairly certain that they would corrugate the ribbons correctly, while a replacement mic would still have probably a 50/50 chance of being bad....
If the manufacturer won't cover it, your choices are basically retensioning it yourself, or writing it off as a learning experience. If you choose to fix the ribbon tension problem yourself, be forewarned that these ribbon mic motors typically do not have tension adjustments, so you basically have to unclamp the ribbon, pull it tighter, and clamp it back down. This is very difficult to get right. Even if you know how to do it, you'll still have about a 1-in-4 chance of tearing the ribbon because of how badly these ribbons stick to the clamps. it is very easy to slip up just slightly and completely destroy the ribbon. And even if you get the tension right, such a retensioned microphone will never sound as good as it would if the ribbon were corrugated correctly.
If you wreck the mic repairing it and decide to replace it, I would strongly recommend that you consider the Apex 205. It's pretty much the same mic you have in a slightly different housing and costs the same price, but unlike most of the Chinese mic resellers, the Apex 1 year warranty reportedly covers ribbon failures/damage.
