Join Date: May 2004
Location: SIN (LEJ once a year)
Programs: SQ, LH, BA, IHG Diamond AMB, HH Gold, SLH Indulged, Accor Gold, Hyatt Discoverist
Posts: 8,792
IIRC, EC261/4 only comes into play if the cancellation is within 14 days from departure. In your case no dice with LX and AV/ LM won't do much when you contact them other than to return the miles and tell you fees may come in 5+ months (they rarely do).
I'd get the miles back ASAP and look to rework / rebook rather than spending infuriating hours with LM on the phone and not getting anywhere. YMMV.