It's most definitely not legal. Send the "collector" a copy of your notice of filing ch. 7 bk and your discharge order and simply refer them to the sections that state all collections activity must stop as of the date of filing.
CH 7 Filed 7/27/15 Discharged 11/16/15
Starting Score: EQ 620 TU 568 EX 593
Current Score (07/13/16): EQ 674 TU 649 EX 674 (FICO's 08)
Cap1 QS ($5350) (Combined QS and QS1) Discover It ($4100) MilStar ($8,600) Fingerhut ($800)
Off to the garden 05/01/16