Bad customer service

I went to Sondor performance foam in Deal party Port Elizxabeth to purchase specific foam for a vehicle I am working on I explained to the lady that I wanted sound deading, heat padded with high density foil foam on one side and must be self adhesive She showed me a sample which they had and I ordered according to what I was shown On collection the 15th of February I received the goods but noticed it was not what I ordered when I arrived home. I contacted them and was told to bring the goods back. I duly did and was informed that they don't supply what I wanted and they could now add the glue to the foam received at a cost of R200 per sheet I was not happy with this as this is not what she said I would get I then asked for a refund and was told they don't do refunds but they will speak to the manager. I have been informed that I now need to produce a copy of my banking details and will have to wait 2 weeks for a refund which is unacceptable as they received cash on the day I given the wrong product

Why cant they give me my money back immediately why do I have to wait due to their incompetence I will never use Sondor foam products or refer anyone to them