Zakaat

Collecting sadaqah money for a surgery which was then cancelled

Q: I collected funds from people specifically for someone's surgery, and these funds include Sadaqah (charity). However, now that I have the money, the person scheduled for surgery is refusing to go ahead with it or is asking to use the money for their personal expenses instead. 

Furthermore, my own parents are suggesting that since we are also needy, we should use this money for our own medical checkups and medicines. 

In this situation, what is the Islamically permissible course of action for the person who collected the money?

Discharging one's zakaat on valuations given of investments

Q: My official zakaat payment date is in Rajab. However, many Islamic investment companies/groups (whether small or big) provide the zakaat valuation/calculation during Ramadhaan some time. Perhaps because people often pay zakaat during Ramadhaan. 

In the case where there are hundreds of investors in a company or example a property, it's not possible for them to provide each investor their zakaat calculation according to each persons individual date. It would be too much work. What should one do in this situation? 

I have been paying the zakaat on my own Rajab date, and when the investments calculations come through in Ramadhaan, then I discharge that amount as well, with a bit extra.

Zakaat on a gold plated necklace

Q: I would like to query regarding 18k gold plated necklace. 

I previously was not aware that zakaat was due on my 18k gold plated necklace. I'm not sure how long I had it in my possession. I am just going to estimate 13 years. I recently also gave the necklace away within this current year. 

I am not sure how much the necklace weight is: will estimate 18 grams, since I am not sure of the percentage/weight of the "gold" in it. 

Will it be okay if I calculate the zakaat on the current selling price of the necklace e.g. The current selling price is R1200 and then to make up for the 13 years =R 15 500 and then pay 2.5% of this amount, will this be allowed ?