Have you thought of crate training your dog instead of pad training? We ran into the same issues with our first Yorkie and it was really frustrating. We went to a professional dog trainer and booked an hour with her and she taught us how to crate train.
We never used puppy pads, and the dog would actually go in a litter box after awhile. We then trained her to go outside once we had a house.
It is a lot of repetition, patience, cleaning up accidents, repetition, repetition, repetition. It takes awhile but if I recall it took about a week to have both ours going outside and not in the house but it is constant work. And they are guaranteed to have accidents inside in the beginning. It is par for the course. Just don't get mad at them. It is your fault, not theirs.
I remember our trainer saying to celebrate how many hours you can go accident free inside. Then days. Then months. We trained two exactly the same way, and it is easy once you understand it.
Also, don't ever ever scold your dog for accidents unless you actually catch them in the act. Once a dog goes, they instantly forget what they did and if you start scolding them after the fact they just see you as a crazy person yelling at them for no reason. Never rub their face in it, spray them, hit them, touch them. They will not respond to that at all. Dogs are all about the moment.
We were even told to not let our dogs see us cleaning up accidents. I forget the reasoning but it all worked in the end as my 8 year old girl has not had an accident inside for years.
Crate training. Patience. Positive reinforcement. Repetition. It will all work in the end and you will be so excited. The reward to the human for success doing this is as great as it is for the dog.
You can get litter boxes for dogs if you want to go that direction. They are bigger and allow enough room for them to turn around and do their pre-pee and poop dance. lol
Seeing that trainer was probably the best thing we ever did for our dogs and us. It completely changed the way we approached potty training them. Just find one that will teach you how to crate train a dog, not pad train. If you want to crate train. Pad training would be the same principle but you would be training your dog to go on the pads, not outside or in a litter box.
Good luck and don't get frustrated. That dog knows nothing of your expectations and is looking to you for guidance and support.
P.S. Use a GOOD enzyme based chemical to clean up accidents. We used Natures Miracle. If a dog smells a hint of urine in your carpet or on the floor, they will be more prone to go there again. If you use vinegar, it sets it. If you use an ammonia based cleaner it will encourage them to pee there again. (urine smells like ammonia or has some in it or something like that)