Doing credit check twice on my profile lowering my credit score😡😡😡

I called in last week on the 18th of July to apply for a Contract phone. I was pre approved then they did a credit check which ofcos lowers my credit score. Yesterday on the 24th July they did another credit check on me that lowered my credit score more and then they don't give me any response.

Today I called in to check what's happening and they tell me that I was declined. I mean why a double credit check? Then you don't send me any feedback!!!