Removing Duplicated Cells Macro

Hey,
I have an excel sheet with phone numbers,looks like this:
A1: (615) 350-1235
A2: (721) 128-2349

I need a macro that removes duplicated phone numbers in case they'r more than 2 of the same phone number,but leave those 2 same phone numbers.

Example:
A1: (615) 123-4567
A2: (615) 123-4567
A3: (615) 123-4567
A4: (615) 123-4567

Wanted result after macro:
A1: (615) 123-4567
A2: (615) 123-4567

Thanks in advanced!