The OP needs to be more specific about what went wrong in the bleep test, if s/he failed on something technical, like failing to cross the line consistently, but otherwise seemed fit enough, it is quite possible that OASC have some H&SW thing such that you can only do one bleep test per day, but they can ask you to some back and do another bleep test quite quickly. The issue might be fitting you in for Phase Two, but even then, given the variable failure rates in each cadre between Phase One and Phase Two, this should not be too difficult.
It probably comes down to whether you failed for some reason that time will correct, ie lack of fitness, or something that was a one off (losing a contact lens mid run, failing to cross the line repeatedly etc). If tiem will improve, then it will take time to get back there, look for 6-12 months. If it was a genuine one-off, then look to fit back into the bleep test and Phase Two in the next month or so.
The bottom line is, an online forum with no recent OASC staff on it, and only a rough idea of the problem, simply cannot offer an accurate answer. The OP is best waiting until his/her Recruitment contact comes back to get a properly useful answer.