Lockers double booked

Two weeks ago when the locker opened for me to put my parcel in there was another parcel in the locker already. I then sent a parcel this past weekend and another lady (not the intended recipient) collected it from the same locker as her own parcel was in, luckily she was honest and contacted my client who the parcel was intended for. Lockers are obviously being double booked which is a major concern