Beneteau has the replacement parts (for Beneteau First 30 (2011):
007984 LINE HANGER BUTTON PLASTIC GRE 3,00 $
010782 LINE BLACK FOR LINE HANGER 2,00 $
But I replaced them with these (recommended on this forum), which work great, requires no drilling and are easily removable:
https://www.amazon.com/dp/B0797LMJF5/ref=cm_sw_em_r_mt_dp_U_0MxhDbCWRPT0S