So, I've got a long time customer that I stopped mowing last month because of constant late payments. She has always been late about a month, but she always paid. In August she was 2 months late and owed me for September upcoming. PLUS she owed me $40 for snow removal that I let slide because she was a lawn customer, I figured she would pay eventually. Well, anyway, in August I stopped mowing because she was so late. I sent her a letter asking for all the money and a deposit to continue service. I got a check for 2 of the months, no snow, no 3rd month, no deposit. I cashed that check, and did not mow. Well, today, I got a check from her for the 3rd month and a note asking why I hadn't been mowing. I am determined not to resume her service at this point no matter what. I never did the mowing in Sept, so I don't want to keep all of the check she sent. The question is, do I cash the check she sent and take the $40 she owes for snow, and send her the balance? Or just send her back the check and ask for the $40 in snow and tell her she's done with? And yes, I know, I should have stopped sooner. But she's a 4 year customer that has always paid late, but always paid. No more letting people slide.