I reckon they'll believe you. Though obvious, did you include a written note with the reason for return?
Next time I suggest you first email their support with the problem. They usually reply with an RMA number & you take it from there. G
P.S. On second thoughts, if it's only 3 broken next time just ask me nicely & I'll send you 3x CD-Rs (not Imation though) for free :-)