Banking on a Memory Test

A funny thing happened to me on the way to the online credit union. Our credit union decided they wanted a more secure website for members, so they upgraded their website to include a more current security check.
After having our password for years without any breach of security, the credit union made the new system so hard to activate; I now have to write down the password and the security answers, when before, I could keep it in my head without having to write down anything.
We now have to use upper and lower cases with numbers and at least 8 letters; not forgetting the security questions, which aren't related to my generation.

 "What's your grandfather's middle name?"  Actual question.  I don't even know that answer; but I am sure a scam artist can probably find out the answer, faster than I can, since my parents have passed.
I could not answer one security question. "What was the street name where you were born?"
The person who came up with these security questions was probably grandfatherly, and lived in another time zone. I actually had to make up names and write them down somewhere, so I wouldn't forget my grandfather's pretend name. Surely, this is more secure than having the real name of my grandfather.

That was not the fun part. I had to called the credit union representative because I had forgotten some part of the security questions. She had to completely reset my password and security answers.

First, she gave me a temporary password; but, before I could say anything, she told me that my temporary password was a combination of my phone number and my social security number.
Making sure she had the right phone number, I said, "797-1234?"
She said, "No."
I said, " Don't tell me you are using our old phone number?  Is it 7891?"
She said, " You should have called us when you changed your phone number."
I said, "It unlisted."
She said, "You have to combined your phone number with your social security number to create your temporary password."
I said, "78812222?"
She said, "No." You had the old phone number right the first time you said it."
Well, subconsciously, I had it right, the first time; but now, that I am thinking, I can't remember what it is.
I said, "What is it?"
She said, " I can't tell you. It's part of the security process."
I said, "You're kidding. I just gave you all my other personal information and you can't give me the numbers of my old phone number?"
She said, "That's right."
I started guessing. "Is it 7818?"
She said, "No."
"Is it 7888?"
"No."
"Is it 8791?"
"No."
After 8 tries, she gave me a hint.
"Take 9 from 87."
I took out my pen and subtracted the numbers.
"Is it 7891?"
FINALLY!!!!
I feel so much more secure, now, having gone through this exercise of trying to remember my old phone number.