Bad service - Mercedes Benz Bryanston branch (Motus)

I would like to file a formal complaint about Mercedes Benz Bryanston branch (Motus)

I ordered a spare key for my car in June. They had said that the remote/sensor key would be ready after 3 working days and the key lock would take 21 working days as it is made in Germany.

It is now mid August, 3 months and I still do not have my spare key. I have zero feedback on why there’s been delays and I am constantly having to reach out.

I would like to escalate to the branch office. Thanks.