If you did not get an email reply immediately, then you need to phone them again.
We booked 11 bikes and cabins for Portsmouth to St Malo ferry and back from Ouistreham for about 3 weeks ago - we go in three weeks time. Three of us were doing the bookings as we had vouchers to use up from a cancelled trip in 2020. They made a mistake on the first try and did not include the deduction for the vouchers. On the second try, this was sorted but no email confirmation received. On the third try, it turned out that they had misspelled my email address on the second call, so I would not end the call until I had received the email confirmation, which came through immediately. All this despite me having a BF account with all my details in it. Our vouchers said that we had to book by phone to redeem the vouchers, but one late addition was able to do the booking on the website including the redemption of the vouchers.