Price change in an item that was ordered

Q: A Muslim company confirmed the price of a product with me at R1800. They said stock will come in a few months.

A few months later the product comes and they say I must pay R2200. I said that you confirmed the price at R1800. The company says that price was then, and now it changed because of USD exchange rate. But previously he confirmed R1800 and never mention USD exchange rate.

I waited months to buy it from them and did not inquire elsewhere because they confirmed the price and my order at R1800.

Please advise:

(1) Is their action as above permissible?

(2) If permissible, is it in conformity with Islamic values? I am annoyed because I waited to buy it from them specifically at their confirmed price. I could have bought it elsewhere all these months.

Difficulty in performing wudhu and salaah due to ill-health

Q: I have many health problems including back pain, incontinence, tiredness, mentally and physically weak, etc. I spend most of the time resting on the bed. Doing wudhu and praying 5 times is very difficult for me. I feel unwell most of the time, doing wudu, praying salah take very long time and I become tired and stressed out.

I don't know any Muslim doctor to ask this and no one else can help me do wudu. Because my illnesses like back pain, tiredness go worse by wudu and praying, can I do tayammum instead of wudu? And pray salah sitting? I tried doing tayammum and pray sitting but still I struggle.

Conversing with Rasulullah (sallallahu alaihi wasallam) and sharing one's thoughts at the Rawdah Mubarak

Q: Is it permissible to converse with Rasulullah ﷺ, share one's thoughts, etc at the Rawdah Mubarak, considering that Nabi ﷺ is hayaat (alive) and will be able to hear one from that vicinity or is it only restricted to salaam and request for intercession?

Purchasing airtime advance

Q: Is it permissible to take out airtime advance with networks such as Vodacom and MTN?

Your account gets credited with airtime and you don't pay right away, but you are charged an extra service fee to get the airtime as you do not have to pay for it right away?

Are the children of one's adopted father's second wife mahrams?

Q: I'm adopted by my parents. My adopted mother then breastfed me so they became my foster parents. In 2021, my mother (foster mother) passed away and my father got married to another woman. She already has three children. Are they mahraam to me? Should I have to make purdah from them? Is it permissible to marry them at the same time?