Pensioner discount on monthy subscription.

I am 72 years of age and have been a member of Legal Wise for a great number of years going back +/- 20 years. In their latest mail drop of increased premiums, it states that pensioners pay only half the monthly amount. This means that for the past 7 years they have deducted double the amount I should have paid. So I phoned them and was told they would change my monthly amount to what I should pay. Imagine my surprise to see that on the beginning of this month I am charged the full amount. On phoning them now I am moved from pillar to post or cut off. Today I have instructed my bank to stop payment on my debit order, whilst also emailing them to cancel my debit order. Why does this company not check via a simple equation check that their clients are paying the correct amount. I have worked in the past with computer programs that check that various parameters are working properly, you would think that with all the money this company is making that they would hire competent staff to oversee that.