There is a clause in the website's FAQ that those who have 2 points less than the passing mark will be given a chance to increase their French language skills. However, I don't know if this is referring to the preliminary passmark (49 or 57) or to the passmark to get CSQ (55 and 63). You might want to take a look at the FAQ's list in Quebec Immigration's website and give them a call as well to verify.
To increase your points, have you looked at maybe:
a) updating your work experience - 6 months has already passed since your submission, so maybe you've already earned another year in your profession?
b) IELTS - any chances of being able to take another IELTS and get higher scores and additional points?
Now, I don't know how feasible it is to get from A2 to B2 in a short period of time, but maybe it's possible if your spouse works on it full time, while you work on it part time as you go to work, or the other way around. By this time, you're probably on your B1 classes already. I know that the placement exam like TEFAQ enables you to be certified at a higher level even if you only took a course lower than that level, provided you really know your stuff. I suppose the key really is in applying what you know in B1 level well enough. Somebody told me that B2 really is more on literary stuff, and that much of the grammar really is in the lower levels; ergo, B2 is more on application. This is just my opinion, though. I'm currently working on B1 myself on my own so it'll be faster since it will take 1 year via AF to finish B1 alone. Don't know if I'll be successful in getting B2 or not, but it's worth a try.
With regards to withdrawing, you might want to check with BIQ for that. It is stated in the website that those who had their applications received from July 8 to Aug 16, 2013 can withdraw. Your demand draft has already been encashed by this time, right, since you already have the AOR? Please also note that if you do get the minimum 57 points in order to be qualified for an interview, you will still need 6 points in order to get the CSQ. It's possible to actually get the full 6 points for adaptability, but it takes a lot of dedication and hard work. If you're able to get French B2 by the time you're interviewed, so much the better. If you're on priority processing (getting AOT points 12 or 16), you might not have enough time. If not (getting AOT below 12 points), maybe you have enough time. Hope this helps. Good luck!