I concur with the others, the 15 or 20 nights at ICs was never a requirement nor ever appeared anywhere in print. The only such qualification that ever appeared in print, in an add for Ambassador in the magazine of the Tel Aviv IC, was "stay at at least 3 ICs in the course of a year" and be among the top 1% of all PC members. The OP has posted his interpretation in two threads, but I suspect he misunderstood the agent. However, where did he ever get the idea that 15 to 20 IC nights was also a requirement as this is the first time any of us have heard of it?