Very rude telemarketer for Netstar

Telemarketer called me on a private number trying to sell me a netstar device for my vehicle. I gave him a chance to speak about his product and kindly told him I dont need this for my vehicle. He was suddenly very irritated and just put down the phone in my ear. This is totally unproffesional and very very rude. Please stop calling and selling your product if you cant do it professionally. Now netstar can be sure that I will never even consider them.