Supply House

On 11 /12 / 19 I place an order for an herbicide called Tri- Lete. I received the order several days later. Today I received the phone call from a gentleman on a fax line from a 608 number which is located in Wisconsin. He kept asking me if I was on a cell phone and telling me that we had a bad connection. I have 4 bars on my cell phone I believe that we possibly had a bad connection because of him being on a fax line.
The individual from Supply House informed me that he was going to ship eight more gallons TRI - LETE and that would complete my order. I informed him that I did not want any more that I had a sufficient amount and he told me the order would be sent out and hung up. I attempted to return the phone call and found out that he had called me from a fax line.
I then retrieved the invoice from the company Supply House ***.
at an 866 number I explained to the person at "customer service" that I had just received the phone call that was rather odd in nature an individual said they were sending me 8 more gallons of ***.
The individual who described himself as being part of " customer service " disputed the idea that I even received a phone call ! He asked me " Why are you calling " ? I am formed him that I did not want to receive the 8th gallons of his product.
The " CUSTOMER SERVICE INDIVIDUAL " informed me that someone must have broken into my files and stolen an invoice and called on behalf of THEIR COMPANY.
" Customer service" hung up on me. I then called him back and told him that I have been self-employed and in business since 1973 and I have never hung up on a customer !
I found both individuals to be extremely rude and not interested in resolving my question as to whether someone was shipping a product that I did not order ? I also wanted to know how someone had my phone phone and knew the exact nature of my previous order ? How could an individual who is not working the company have a copy of my invoice with my phone number?
The individual at " customer service " returned to the idea that someone had broken into my files and retrieved my invoice and then called on behalf of Supply House !
I am unclear as to whether this is a legitimate company ?