[30 day trading limit?]

I have had my account for a little more than 8 years, and this is my first time ever buying linden. It said my trading limit was up to 100$, so I purchased L$ with the estimate of 100$. I tried to purchase more the next day and it says I have a monthly trading limit of 100 dollars, does this mean I have to wait for a month until I can purchase L$ again? And does this mean every time I buy linden I will have this tradling limit, or is there a way of changing it?.

[How do I buy linden? It always says I exceeded my transaction limit. ALWAYS.]

So I've never bought linden before and now I wanna buy a big quantity and I know I cannot exceed the 30.00$ so I'm trying to buy less linden but everytime I try to buy linden it says I exceeded my transaction limit when I am not evne exceeding and I cannot buy anything, help please?