Sunninghill and Wendy are driving your name through the mud!

I went for an eye test in December and also ordered new glasses. Once I received them, I was asked to pay the copayment / shortfall, which I did. 2 months later I went to collect my trial contact lenses, where I was not asked to pay any further money. A month later I get a rude and threatening email from Wendy, saying that they will hand me over to lawyers. I asked her for proof of previous requests for outstanding money, quotations and invoices showing how much I owe and an explanation as to why this was not requested previously. She responded with rude and condescending emails basically saying that I am stupid and I need to pay the money before she hands me over to lawyers. Dear Specsavers: this branch is obviously poorly managed, Wendy is tarnishing your name further I cannot even imagine what her people s****s are like to customers in your branch and it is clear that I do not owe you guys a cent. Wendy even admitted that their paper work is not in order and she did not send me previous emails yet she sent a rude final demand. I would like the head office to please set this useless branch in order and also get Wendy to call me to apologize for wasting my time - I had to sift through previous emails and quotations to give her a breakdown as to why I do not owe the claimed amount.