Metro PCS On Sprint Diamond Issue

[violentz313]

So my brother is having a problem but dosent post on here so ill post for him. He has a sprint diamond that he wants to get activated with metro pcs. We have seen that it obviously can be done since other people on here already have it.

So heres the problem we tried going to 3 or 4 different stores that claim they flash phones to metro pcs yet everwhere we go they say oh sorry we cant do it with the diamond. Now obviously i know this is not true so where should we go from here should he just give up and sell the phone to someone with sprint any other options for getting it activated?