complain for company

I was working for sorbet they deduct my pension fund fee.then i was found out that i was not registered .when i contact bargain council they told me i must open a case because is ***** for employer to deduct your and not paying pension fund.they told my employer must pay back all the money was deducted from my salary. when i contact my employer he doesn't respond he just blue tick me.i want my money back please help me.