Metro Pcs he was rude and charged me an extra fee that i had not ever paid before..and refused to credit or refund the phone i purchased 02/04/13 cockerhill, Texas

I went inti the Metro Pcs store off I 30 and cockerhill around 5pm on 02/04/13.I already have an account with Metro I purchased a new phone the retailer charged a 15.. service fee for not doing anything for me.I was upset and I have been trying to get the charged credited to me I called the call they refused and said they no phone number for corparate office for Metro Pcs.I went to store and wanted a refund on phone and employee of Arabic decent refused he argued with me and was very rude.when i purchased phone he had charge my debit without telling there was service fee of 15...the refused to refund my money for phone because Iam already a customer there were no signs posted store regarding policy.