No upgrade phones available as per Virgin website

I am due for an update from Virgin Mobile and decided to invest in a cellular device as advertised on their website. upon requesting an update I was offered the lowest phones possible, and when I enquired about the range of phones I wanted, I was told that they did not have the particular models in stock. I have phoned Virgin mobile several times without a response. My latest reference number is RLM ***4. A very poor company!