Asking for a refund due to the purchased item being faulty

Q: I purchased a second hand aircon from a fellow Muslim brother. He promised me that its works perfectly. I took his word on it and paid him R2000.00 to install it. R1500 for the unit and R500 for installation. However the aircon did not work from day 1. I kept on messaging him for 2 months that its not working but he kept insisting it is and he continued ignoring my messages. I got fed-up and asked him to please remove it as its not working. Without my knowledge he came to the house after the 2 month period when my dad was there to repair it, and he admitted to my dad its not working. He said he will bring the parts to repair however I told him to remove it. He then took 3 weeks to come and remove it and told my dad he will do a bank transfer for the refund. A week later after messages after messages he only refunds me R1000.00 and tells me that because of his time and labour he is only refunding half my money. When I explained to him the unit costs R1500.00 as per his invoice he said no the unit was R1000.00 but when I sent him a picture of his invoice he admitted its R1500.00 and he will only refund the R500.00. It is now gone a week and he has gone back to ignoring my messages and no refund has been received. I ask you respected mufti, what must the total refund be? Should it not be for the full R2000.00 because the aircon did not work at all. Can I lay a charge of theft against this person.

Christmas food

Q: What is the ruling on eating Christmas food? If its haraam to take, then when we have been given, can I dispose of it or will Allah punnish me for been Al-mubazzir?

Wearing niqaab with decorations

Q:

1) Are women allowed to wear niqaab with long flaps and also have decorations on it?

2) Is it permissible to get a piercings on the top part of your ear?

3) If a burqa I've been performing salaah with is only see through in the sun, will salaah be permissible and do I have to make qadha of the salaahs that were performed?

4) Is is correct for women to walk a distance to attend the weekly community ta'leem?