Threatening behaviour

On Nov 29th I ordered a meal from Popeyes. I realised after the courier had left that part of the order was missing, I immediately contacted Uber. They responded threatening me, that complaining about missing orders was a pattern of behavior for my account. I responded saying that in the few years I have been using their service I had never complained until yesterday and could they provide proof. They did not, but responded again threatening me, this time to deactivate my account. I have sent them two further emails stating this behavior is unacceptable and to provide proof of their accusations.

They have just responded again saying that they do not give refunds to a profile like mine, again I have asked for proof as I have never had a refund. I get numerous discounts due to rewards eg DM insider, Vitality etc.

I do not understand how a business like this is able to threaten and slander clients with no recourse, for an error they made.