If its tracker mortgage related they have put a stop on some investigations till the Central Bank review. When you say its with their investigations team since last February - did it not go into mediation at all?
It is related to wording regarding the interest rate applied to our mortgage contracts and whether it comes under unfair terms in consumer contracts. Complaint went to mediation last spring and went to investigation last autumn.
Not sure when they will revert - I have a similar time line - complaint in feb 2017, in mediation till October 3017 when it moves into investigations. You should ask them have they issued a letter to finance institution looking for their position (mine issued end Jan and the bank have till end feb to respond) so I will be following up with FSO in March re timelines. Your complaint could be on a similar time line so I would call them and check. FYI, when my complaint went from mediation to investigations the mediator warned me that investigations are working on a 12-18 months time frame!!