Writing out three talaaqs in the state of duress

Q: Mufti Saheb, I was forced by my family to divorce my wife by writing on a page and signing that I am giving her three talaaqs. My family threatened to beat me up if I did not comply. Hence, I was forced to write the following: “I, so and so, am giving my wife three talaaqs.” Are the three talaaqs which I wrote valid or is my wife still in my nikaah?  I did not verbally issue the three talaaqs.

Paying for one's poor neighbour's renovations using zakaat money

Q: The following has occurred and I am not sure if it counts as my zakaat being fulfilled.

We have a neighbor who is a worthy recipient of zakaat. My parents were in the process of helping them amend some part of their home when my zakaat became due. I had informed them of it and so my mother gave the man who is doing the fixing, the money to buy the tools and materials with the intention of zakaat for our neighbor. It was not given to the man doing the fixing in lieu of his labour but rather for the material needed to fix our zakaatable neighbors house.

Is my zakaat considered as valid ?

Receiving the normal price of an item when returning an item instead of the discounted price

Q: If a person sells a certain item and a discount was given to the customer and thereafter the customer wants to exchange the item or be refunded for it, will it be permissible to subtract the discount given (proportionally)? If the discount is not reversed will it be regarded as interest?