Very Frustrating service!!!!

I have tried to get Cavendish Square Nespresso to contact me for three days. I have spoken to 3 call centre people, I have sent two emails to the Nespresso head office. I have filled in the contact me form that I was asked to do. I am still waiting for someone to contact me. I bought coffee miugs and I was given the wrong size. I went to cavendish Square to exchange them and was told that they don’t have stock of the one I want but don’t worry they’re getting stock in on Wednesday and they will call me the minute it’s in. I was told to leave the incorrect mugs with them and the exchange will happen when they get stock. I’ve not had a phone call, and even after numerous attempts at getting them to call me back they have not done so. It is incredibly frustrating not to be able to talk to a branch especially under the circumstances. It’s also incredibly arrogant of Nespresso to expect the clients to drive to a store to get an answer to a question!!!!! Imagine a drive there and there’s no stock and I have to drive home again, and then repeat the whole exercise every single time I want an answer to to my question??????