Can't beat the Bluelab Truncheon meters for reliability. I have used the expensive in rez tri-meters but after using the Bluelab products I would never go back.With luck, they will get you through 3 mos. Mind you, I used to use the Hanna non-waterproof pHEp pen meters, which lasted on avg, about 3 mos. They are now sold as 'disposable' Hell, I coulda told 'em that.
Good luck with those, but when you can put about $100-120 into a meter, try a Bluelab Truncheon (not Chinese copies as found on ebay) for TDS and a Eutech pHScan1, both of which will last many years.
Yeah, the place I bought it from said no returns, and I have to take it up with the manufacturer... It's been sitting upstairs for about 4 months.Sorry to hear it. That does much of sucking, esp if you have mail ordered and have to pay return shipping...
Good ol' Am Ex will do it for you everytime toofuckers.
Hope you paid with a cc so you can just enter a dispute with your card provider, who will charge back the seller. Make it so the twats get paid by satisfying you.