> do i have to contact my pension provider and ask for an Rac cert and then send it to inland revenue.
You should only need to do this for once off payments/top-ups etc. For regular contributions the relevant form (e.g. RAC cert, PRSA1 cert etc.) and a letter to Revenue should result in your tax credits being reviewed to grant you tax relief on the "standalone" contributions. For once off payments or top-ups you can simply write to Revenue with the details and they will probably refund tax as a lump sum. That's the way that I've always done it anyway. Are you sure that you meant Inland Revenue and not Revenue? If so perhaps you are in the UK in which case things might work differently there compared to here in Ireland?
> how can i varify that I have claimed all the tax back that i am entitled to
You are entitled to full tax relief at your marginal rate (20% or 42%) on amounts up to the relevant age related pension tax relief limit (or 42% on whatever amount you paid 42% tax on and 20% on the balance):
You should also be entitled to PRSI relief which you claim back from Social Welfare but they are still not processing such claims as far as I know: