no date on cash memo

Location/place: faridabad

Name of company/service: home shop 18

i purchase a hp pen drive from home shop 18 in month of july they gave me cash memo on home delivery but there was no date on that i call them again and told my issue they said me that they gave me a another copy of cash memo but they do’nt gave me acopy so iwant to look in to my matter and solve it as soon as possible thanks