Working Family Payment vs pay rise, does it cancel itself out?

I’ve been working with the same company for the past 16 months and I’m currently on the lowest point of the pay scale (€14.55 to €16.55 per hour). I started on €14.55 and was told after my 6 month probation that my hourly rate would be reviewed, this never happened. After a further 6 months, I was again told it would be looked at, but there was no change.

I asked again before Christmas and was told they would have a look at it and that I should remind them in January, as they are “very happy with my performance”. My feedback has consistently been positive and I get on well in the role and have all my qualifications to do the role.

In the meantime, I was approved for Working Family Payment, which actually brings my overall weekly income to above the company’s top rate of pay. Because of this, any increase of €1–€2 per hour would largely be offset by a reduction in my Working Family Payment, meaning there would be little or no real financial benefit in asking for a pay rise for a fourth time.

On top of that, eligibility for Working Family Payment now also qualifies me for the Fuel Allowance this year, which makes it seem that remaining on €14.55 may actually work out better over the course of the year.

My question is whether there is any real point in going back to my manager yet again to request a pay review for a fourth time, particularly given that previous assurances have not resulted in any change. It also appears that moving to the top rate of €16.55 would largely cancel out my Working Family Payment and Fuel Allowance which kicks in this year for those on WFP, potentially leaving me worse off overall across the year.