Prokard Waste of Time !!!

I am a Protea Hotel Prokard Member for over 4 years. In the past I have received excellent service, with booking efficiency. However after 4 years of membership the Card has become an utter and absolute waste of time for the following reasons. You are rewarded with Free Stay Vouchers when membership is renewed. During the course of this year, everytime I have tried to make use of these free vouchers for membership which I have paid for, I cannot. I tried to use the pay one stay one night free voucher in October and could not, considering that it was an off peak time, I contacted the call center where the staff were rude and unapproachable. I have accepted that I could not use the voucher at that time and then again in November and again in December, however, the buck stops now, I want to redeem my vouchers for my Birthday Stay in Cape Town in February and I cannot !!! This is absolute *******. So effectively I have paid the membership and cannot use the vouchers which means that I am getting nothing for free, and rather the Protea Prokard Enterprise has made a profit off me this year as I cannot use the vouchers! I am extremely unhappy and unimpressed!