Warranty means nothing

Bought a battery which carries a 18 month warranty and after 10 months had problems with it. Took it back and had it tested and according to them there was nothing wrong. 2 Weeks later the same problem but this time it would not start even after jump starting it. Contacted them and ask to send somebody to assist, but to no avail after phone was put down in my wife's ear after they said she sweard at them after she said how the \Bliksem"must I get the car there"