How do I block calls on my MetroPCS Zmax Pro (Z981). I have been through as many of the call options as I can find, I Googled it and found where someone said to long-hold the number I want to block and the option would show yet the all I am offered at that point it is a "copy to clipboard" and "Edit number before call" option, no "block call" option. I have been getting obvious telemarketer calls from the same numbers daily for the last several months and I'd like to block them. I realize they'll just change to a different number but its a start.