voucher redeem by serial number/reference method

purchased an ott voucher on the 06 april at 18;00 unfortunately i did not redeem the vouchers immediately hence curently i am finding myself in a predicament whereas the documented proof that i am in posession of unfortunately has the pins blurred out by my fault.. currently i have been trying to identify the numbers soley so with no luck.... i am requesting your help and your response would highly be appreciated... EFFECTIVE IMMEDIATELY