Chemsico Ultra-Kill Ultra-Kill Weed & Grass Killer concentrate is a lousy product St. Louis, Missouri

I've used Round-Up before with decent results but this time I thought I'd save a buck or two by buying Ultra-Kill Weed & Grass Killer concentrate.  The 32 oz. bottle is supposed to make 12 gallons of spray.  I mixed a quart spray bottle at the recommended concentration and sprayed some grass and weeds that were encroaching on an ornamental landscape area.  I expected them to be dead the next day but they weren't so I waited a couple more days.  They just kept growing so I doubled the concentration and sprayed again.  3 - 4 days later a few had turned yellow on some of the leaves but most were just as green as ever.  I doubled the concentration again and sprayed a third time. 

Now 3 days later two or three weeds look like they may have died but most everything is still green and growing.  By now there are only about 6 - 8 oz. left so today I poured that full strength into my spray bottle and hit the weeds a 4th time.  I don't know yet if that worked but I shouldn't have had to spray full strength on a concentrate that was supposed to make 12 gallons.  I got less than a gallon and may not have killed the weeds in a fairly small area (about 35 sq. ft).  The bottle says it should cover 3,600 sq. ft.  At that rate I did not save money... I wasted money.  No, I am not happy with this product.  I'm not only disappointed, I'm disgusted.  Time AND money wasted.  I will be taking the empty bottle back to Lowe's and complaining there too, and buying a different brand next time.