******* deductions from salary

I am frustrated with SAPU. They started deducting money from my salary June 2014. I have managed to get the deductions stopped Sept 20015. I have sent them the proof of deductions and have patiently been calling every month since Sept only to be told that they will call me when my cheque is ready. I have made another call today only to be told I must get Persal screen prints because the proof I have sent can easily be amended. I was employed as a civil servant not a police officer. i have never signed up with SAPU before but was a member of POPCRU. I have left the SAPS more than 7 years ago. The deduction started all of a sudden last year. What must I do. I have spoken to a Lesego and a Mr Gwangwa. they have our records, they know since when they started to deduct, why are they making it complicated for us, who did not give them permission to make deductions from our salaries, to get our money back.