You just have to keep calling. Having the number saved and programmed to push the buttons for you is going to make it a lot easier. I have initated about a dozen transfers, 6 in the last few weeks and it does not take me more than an hour to get through with non stop calling. I've gotten to the point where people are suprised when I conference them for their half of the transfer.
Program the number into your phone as such: 1-800-731-4000,1,,,,,,,,4,2
Each comma is a 2 sec pause, you phone will dial the first number then it will pause then push the 1 then pause for 12sec (to wait for the annoying new recording) then it will press the 4 and so on.
If using Android, with the keypad open, start entering the number, then press the three dot button in the top right corner and here you will have the add the pause. Add as many pauses as called for.
If using an iPhone, you have to add the number in a new contact. When you add the number there will be a button in the bottom left corner of the keypad (+*#), select this and there is where you can add the pause as needed.
Doing this all you have to do is press Send and End when you get the "We're sorry..." bit, hang up and just press send again.