Dealer just tried to rip me off.

So I'm kinda new to the SweetLeaf, only been smoking for about 4 months, about every other day. And i've been buying from a really good friends brother. Who I'm also pretty good friends with. He sold pretty good mids, but decided to stop selling and smoking for a bit to get a job and so I got a number for another dealer. I text him going through the movements etc. and he asks how long i've been smoking and I told him not long. So I ask how much for a G, he goes " This is some dank ass bubble Kush crossed with trainwreck, so it's 20 a G." I'm like i'll have to see it before I buy it for that much, but if it's what you say i'll take 1/8th. (He was just gunna drop it off but because I wanted to inspect the "Dank" I told him I'd just walk over. So I get there and (Him knowing I haven't smoked long goes through the procedures to TRY and rip me off). I sit down and he starts to weigh it about 10 feet away and I'm not really paying attention cause a buddy from school was there and the dealer comes over and asks for the money. And I ask to see the bud first. He had it all in the bag already hoping I wasn't going to look. So I take it out and it's some of the nastiest looking regs I ever seen in my short smoking life and I get up and say " I know I haven't been smoking for long but you take me for a fucking dumbass? This is the shittiest shwag I've ever come across and it's your kind of people who give this plant a bad name. And that's not even close to a fucking 8th." So I walk over to the scale and weigh it and it's only 1.9. So I start to head towards the door and my buddy ( Who I've known since like 4th grade((Has no affiliation with this dealer)) stops me and walks out the door with me. He then says " Yo Bro I didn't know you smoked. Next time you need some Herb just give me a call, This guys a dick and will try and do that to new buyers." Hands me an 8th of good headies and walks away. No charge.

Anyways, this ever happen to you? What did you say and how did it play out?