The UR5e and installed tool cable arrived correctly, but the promised spare kit has spent 55 days in 'next shipment' territory, and I cannot sign the delivery complete while its extra cable has no parcel reference; what would you ask for beyond another cheerful assurance?
Ask for the missing items against the accepted contents list, plus a specific proposal to supply them. Do they actually acknowledge the shortage? A reply about future shipping may avoid that question entirely.
They do acknowledge it and say the kit was left out, but have not identified any consignment that contains it (I checked the replies again before answering).
I'd ask purchasing to compare separate shipment with an agreed credit and another source. Our spare planning once waited on the same reply for ages, while nobody knew whether an alternative was even available.
Purchasing is checking that, though I have asked them not to accept a credit until support confirms the alternative cable and its availability; solving the account would not put a spare in stores.
Has the seller offered separate supply in response, or is that still only your request? I would keep their proposal and your alternatives distinct in the shortage record.
Still our request, no new offer from the seller; I am keeping the kit outstanding and the installed cable recorded separately, so nobody can mistake one for the other.