EDIT: Crisis averted.

The landlord has no respect for me and my brothers, however he would speak with my dad so he gave him the answers to the security questions we needed to tell the deposit holding company. We're very lucky!!

We've moved out of a rented property after nearly 14 years. When trying to get our deposit, a holding company asks us 'security questions':

1. What was the amount of the rent when first renting?
2. What is the moving in date?

The landlord is absolutely awful and has no incentive to help us so he won't on this. He's too busy taking selfies in his brand new £200k Mercedes.

We don't have records on the original rent because after our mum died, we had to close her account and start fresh 8 years down the line... As for the exact date of moving in, not a clue!

Any idea what I can do???