office depot send me my rebate please!

I did everything I was supposed to do in order to submit the rebate, However I didn't get any response from office depot rebate center after almost 2 months and I submitted the copy again, and called the rebate center, and the agent told me it is ok, then on october this year, I checked the status of my rebate, it indicate my rebate got rejected as I postmarked it late! This is a really a scam, as they can claim you never received customer's rebate submission, and when the customer resubmit it you deny it.I feel so frustrated on this 70.00$ rebate, and I called office rebate center, they told me they can't help me!

The tracking number is KRHM-0055-7607the offer number is OD1602368.Those items were purchased at st.louis, MO 63108 store 2529, the trn number is 3692.