Boy, does this sound familiar. It took us over three months (not as bad as your situation, but equally frustrating) to get the checking account turned over from the old treasurer to the new one. Problem was, the person that had the treasury was the President two years prior and defaulted to the treasury because of problems that developed.
When I took over as President, I was President in title only because the old one just would not turn over the gavel. Finally, I got a tad agressive over that and we got it done. Meanwhile, we only had one signatory to the checking account, and that was the treasurer. We did not know what was going on with the money because that person was the only signing checks. We changed the rules. No checks can be written without prior approval by members at our monthly meetings. Nothing gets paid until we all know what is being paid. The exception to that rule are the basic necessities (Porta Potty, lawn maintenance, and emergency expenditures). These items can be paid by a phone call by the treasurer to the President who will authorize payment. Any item over $250.00 requires two signatures.
Shortly after I was elected, the treasurer got very upset. He did not want me in. I also write the club newsletter. So, I incur expenses for printing and postage. I had a accumulated postage and printing bills for over 6 months because he did not want send the check to me in the mail. He did not want to spend the postage..

We had some heated discussions about that over the phone. He wanted me to come to his house and pick up the check. I wanted him to just mail it to me... he was never home because I went there several times to collect the money and his wife said he was not home.
My big concern was that we had a good deal of money in the bank, in a CD, and he had control. It was set up that way when he was President then President/Treasurer. I wanted to make sure we still had the money. In the end, we did, but he decided to leave the club because, in his words, he could no longer support such an opressive group of leaders. So be it. We're far better off now. For the first time, we have money in the checking account and in the CD, and will add to the CD with our first surplus in about 5 years.
Keep up the pressure, and do as someone suggested. Get together with the officers and decide where to proceed next. If it involves legal pressure, you have every right to pursue that in the name of the club. Remember that this is not their money, the money belongs to the members of the club and they have no right to hold it back from "you" as the new President and other officers.