Call centre and drop-off point not aligned on process

I forgot to add a user manual to the item that I returned. Takealot contacted me and asked me to take it to the drop-off point under the same return reference number, which I did. At the drop-off point, I explained the problem only to be met with "Your return reference number isn't working."

Why does the call center provide instructions that cannot be handled by the system and inconvenience the customer? Looking at these ratings on Hellopeter I can see they don't give a flying hoot about service.

Emailing the call center again, and they still insist I take it to the drop-off and use the same number.