Contract Breach options?

I have a six month advertising contract with a local magazine that states, "Must place ad within the first 5 pgs of the magazine each month". The forth month they placed my add on the page numbered 6, and when I challanged them they said, we do not count the cover as page one and specifically stated - " Page 1 begins on the first right hand page inside the magazine and the your ad is actually on the fourth page of the magazine. Even if you count the inside front cover as page 1, your ad ad would still be on page 5". I replied when I look at my ad, and look at the bottom of the page it shows page 6. If it reads page 6, then to me it is on page six. All the pages are numbered with the page before at 5, and the page after as 6. What obligations and recourse do I have? If this is breach of contract, does it just breach the current month meaning I should not pay anything for that month? Or does it allow me to void the contract for the remaining 2 months? Or does it mean the entire contract was breached and the amount paid for the previous 4 months is recoverable?