We have a cat and I can't stand her.
She's probably about 17 years old now. For the past several months, every couple weeks, she'd pee on the floor by her litter box. Sometimes she'd drop the kids off there too.
Many times, it's even when the box is clean. Most times, the pee would run under our laundry dryer and I'd have to first slide a paper towel under to sop up the excess, then move the whole dryer to properly get the rest and clean. Big pain.
We found some mattress pads in our garage recently. They're designed for kid's small (crib) beds to go beneath the sheet and soak up any accidental bed wetting episodes. I started putting them on the floor next to the dryer to help with the problem. We also got her a lower litter box, thinking she's getting older and doesn't want to jump in this big box we had for her.
Anyway, it worked in that she'd go in the box with an occasional pee on the mat, which was easy enough to clean and no pee under the dryer. Trouble is, the past 3 days or so, she's been using the mat exclusively. Pee, poop, it doesn't matter, and all the while, the box is untouched.
So, long story longer, the dilemma is, am I training her to not use the box because of the mats? I gotta admit, it's gross, but it's easier to clean than a litter box. Plus, I can just flush the poop. Now that I think about it, maybe that's the way to go... put mats out, no more litter, no more dust/litter everywhere, fairly quick clean up.
Hmm. Quite the dilemma.
* I think the first thing (if you haven't already done so) is get a vet to check your cat's overall health, esp. for a urinary tract infection. Might require a blood test. If she just suddenly won't use a box at all, that could be part of it. They may recommend a prescription food (urinary-tract friendly food), or sometimes you can find the appropriate food at a pet store, if a vet suggests that.
*Do you use a hooded litter box? My late cat wouldn't ever use a hooded litter box (not even a "half-hooded" litter box), and many cats either won't use it, or won't properly use the box unless the hood is off. You might consider a litter box with a lower rim, or at least a lower entry way that's easy to get into. I think older cats seem sensitive to that.
*What brand litter do you use? All cats are different, and some are more comfortable with one brand than others. Some can also be sensitive to scented-litter (there are usually "unscented" versions available on most brands).
*From about 1998 to May 2010 (when Molly was diagnosed with congestive heart failure and then started pooping outside her litter boxes though she still urinated in them OK) my cat really liked Dr. Elsey's clumping litter, which is available in most Petsmart stores (Petco doesn't carry the brand). It's billed as for cats who won't properly use other litters and it did work for Molly for many years.http://preciouscat.com/
*"Cat Attract" is their sub-brand (red plastic packaging) meant for cats who aren't using litter boxes properly. I'm not convinced it's a whole different than the regular Elsey's brand per se. I can't guarantee it'd work but it's probably worth trying a bag -- bearing in mind you can't really return litter once opened, most places.
The Elsey's brand also sells a "litter box attractant," although if your cat simply doesn't like or feel comfortable with your litter, that probably won't help.
When I get home, I'll share some links I'd found with some suggestions to try when cats won't use a litter box.
In Molly's case, I tried probably 5 different litter brands and 3 different litter box models to get her to poop in the right place again. What finally worked for the last couple months of her life was a $2.99 "disposal litter box" you can find at pet stores and some grocery stores. It comes with just a little clay litter sealed on the bottom, and you tear the lid off. For whatever reason (maybe the low sides), she finally started using it again. (she would use it for both urinating and pooping, and sometimes would still urinate in her regular old litter box OK). Since it didn't use clumping litter, I had to throw it out after a week or so (even after cleaning solid waste, the urine soaked the clay litter quickly), but that certainly beat cleaning her poop off the floor or carpet.
So, like you with your pads, I had to improvise.
You say you hate your cat, but you seem like someone who is trying everything to make it work, and I think you should be admired for that, regardless of whether you're crazy about the cat or not.