Complex sentence: MMM Nigeria reopened on 13 January, 2017 but has been plagued by grievances from participants concerning delayed or unfulfilled payments, owing to fear amongst participants, some of whom have moved to new ponzi schemes.
Split into simpler sentences: MMM Nigeria reopened on 13 January, 2017 but has been plagued by grievances from participants concerning delayed or unfulfilled payments. This has been attributed to fear amongst participants, some of whom have moved to new ponzi schemes.