Nissan Gateway worst dealer ever, don't deal with them

I Had purchased a booth pipe for my car, after making the purchase i found out that my warranty covers the pipe, i then did a warranty claim for the pipe and once it was approved i went back to the dealer for a refund, its been 10 days and they still have not refunded my money, i spoke to the cashier lady that started the process and advised that i will get my money today the 19th but it still has not been refunded, is this the terrible service they offer to clients, this is by far the worst dealership i have ever dealt with, previously they repaired my car and till now my car isnt right all my panels on my dash is popping out after they replaced the heater box, this dealership just destroyed my high end car that i paid so much for.........