How do I return a dremel pet nail guard that does not fit the dremel.I ordered it on line and do not have a receipt

Use your credit card information/ statement and or debit card information statements to have leverage to help you.

From home depot ? So i can't return it to the store. ?

You have to send it back so when's it came from

I would check with the customer service desk, without a receipt, I'm not sure what else you could do. Possibly if you have an email from the online order print that and bring with you