I’m really having had time with online booking in FlySafair: they require a booking reference with 6 digit number yet the booking I was given by them only have alphabets

I’m really having had time with online booking in FlySafair: they require a booking reference with 6 digit number yet the booking I was given by them only have alphabets. This inefficiency is inconveniencing me because now I’m unable to check in. I’ve always have pleasant experience with them it’s the first time I’m facing this glitch.