According to which price should old debts be settled?

Q: A Muslim bakery sold bread on credit fifty years ago valued at Kenyan Shillings 6500/-, and the price of loaf was KShs 0.75 (75 cents). At that time the debtor had failed to pay. Now his kin want to settle the debt when the price of a loaf is KShs. 50/- and is ready to pay extra over the 6500/- owed. Can the Bakery demand to be paid according to the current price of a loaf of bread? Or can they accept the initial debt of KShs. 6500/- plus the extra the debtor is willing to pay seeing the difference of the cost of loaf today and fifty years ago? As the actual currency is gold, can the debt be evaluated according to the price of gold fifty years ago and now, i.e., the amount of gold that could have been bought of KShs 6500/- fifty years ago and the value of the same weight of gold at the current local market be the repayable debt? The owner of the bakery (now run by his children) died many years ago. Please advise.

Selling glue to someone who is sniffing it

Q: At our store we stock a large variety of products including shoe makers products. Recently we have been getting a customer coming regularly to buy shoe glue only. The staff have brought it to our attention that he is buying it to sniff. After this I have observed the following:

  1. He does not buy any other shoe makers products.
  2. He buys more glue on a single trip then any other shoemaker I remember serving.
  3. He never has any shoes or shoe makers items in his hand when he comes to the store whereas this is usually noticed  on most shoemakers.

So it is clear that he is sniffing the glue and not using it for shoes. Is it permissible to continue serving him knowing that he is using the glue for sniffing?

NB: Our store does NOT run on a self help system so he has to ask for the glue to be given to him which makes it very easy for us to stop supplying him if necessary.

Holding the Qur'an and taking a false oath

Q: 

  1. A person who has two wife's and at present is living with the fist wife, the second wife made the husband touch the Qur'an and made him say I am your only wife and the first wife isn't my wife she (fist wife) is my sister. The husband said this to make her (second wife) happy and when saying this he had the intention that the first wife is also his wife, what is the Shariah ruling for all this?
  2. Will the second wife  be sinful for making the husband say the above touching the Qur'an?
  3. Will the husband be sinful for touching the Qur'an and saying the above?
  4. By doing the above does it effect the Nikaah in any way?

Doubting if one has settled his accounts during his student days

Q: A person has been attending a madressa. At the madressa there is a tuck shop which allows the students to take things on credit. As a student many things were bought on credit and paid later. A few years later the student has doubts in their mind as to whether they have paid their accounts accordingly. What can the person do besides asking Allah for forgiveness?

Working as a teller in the bank

Q: I have a job interview working for a bank in the USA. I was told that it is haraam to work for an American or foreign bank because they deal with interest rates (RIBA). However when I work there I will be at the cashier, depositing the clients money in their account, not directly with riba. Please advice if this is haraam or halaal?