Kia Picanto failure

Good morning friends.
I have the following problems with my Kia Picanto.
I just changed spark plugs, because it gave a flame and lost strength.
When they were removed, I realized that they were all burned, I thought that in the workshop they had scammed me, I took the sample for a sale of spare parts to replace them, after that has not passed any month and the Fallon has it again loses strength, I am sure that when they remove them I will have the spark plugs almost burned again. What type of spark plugs or brand should I use?

The other problem I have is that when using heating it stops working and all the water filters in the car on the co -pilot side. This is complicated because that makes all the water of the car get lost, both of the radiator and the deposit. I have stopped using heating but I use it with cold air a rainy night and the same thing happened to me, what can I do?

Thanks for your answer.

Hello the spark plug failure is the excess of fuel that is entering the combustion camera that can be sensors or a lot