Bad customer experience

I am working as a barber with a min income of between 8000 to 16000 deposited in my bank account. I went to apy for an iPhone contract to build my credit record. The store didn't assist me. They told me that my salary should be the same amount everymonth. What I asked myself financial advisors, brokers, estate agents etc are commission based why do they get contract? For variable salary one needs to calculate the avarage which is also done by the bank. I had an iPhone which I was ******. I need an iPhone urgently to access my info