Creative accounting

I have owned this time share since 2001 every 2 odd years they will entice you too purchase more points but not deliver when needs be, recently I fell prey again and now converted these points into 2 guaranteed weeks and ended up spending much more money, only to discover when requesting settlement figures to pay these 2 weeks off that they have been ripping me off since 2001, they owed me amounts which now conveniently they say they do not, I have forwarded them statements I received confirming these amounts are in credits (that they owe me) and now the excuse was the statements issued previously where incorrect what a load of bull. They also confirm that if amounts are settled within 12 months I get back the interest I settled this in May and to date I never received my interest amounts paid, wonder what excuse they going to come up with next. When they converted the points to 2 weeks, they ripped me off yet again I purchased the points are R1500 they bought this back at R750 odd the reason they gave me was because I used the points which I never did because there is never availability when you want to use it, again **** as when you buy a house do you sell at a reduced rate?