Lewis bad service

My lewis account was in arrears. I then received a visit at work by 2 lewis employees. They ladies said that thyre manager was demanding the funds or the goods i had purchased. I then paid the funds and was told proof of payment would be given to me. A week later i call asking about said proof of payment. The lady i spoke to was so rude, shouting, even going as far as saying i am petty when i asked her to not raise her voice at me. I tried to explain that as per my agreement with the lady i spoke to when making payment i was expecting my proof of payment same day, that did not happen. What kind of customer service is this where they shout at people over the phone? I am so upset with this