Sewage smell from the pump tank comes up through the shower drain that the smells up the whole basement, when I leave to work & return in the morning the smell is awful I pour bleach/pinesol into the toilet & flush as well as the shower drain. The smell temporarily leaves when I shower when I use the toilet it won't flush immediately it backs up & clears on its own later in the night or next day. I need help to reed off this problem when my daughter visits me the first thing she says is " Papi what's the smell, it smells like dodo " what can I do ?

The sewer line is not only blocked, it sounds like there might be no trap under the shower. (A trap is a bend that holds water to keep sewer gas from backing up.) But if the sewer is backed up, the trap, if any, is too. Your cousin needs to pay for a Roto Rooter type company. Sewer gas can be worse than just annoying.
Drains can be just clogged, but they also can be broken or so full of tree roots that they can't be cleaned. This is determined with a fiber optic camera. It can get expensive.

The sewer line is not only blocked, it sounds like there might be no trap under the shower. (A trap is a bend that holds water to keep sewer gas from backing up.) But if the sewer is backed up, the trap, if any, is too. Your cousin needs to pay for a Roto Rooter type company. Sewer gas can be worse than just annoying.
Drains can be just clogged, but they also can be broken or so full of tree roots that they can't be cleaned. This is determined with a fiber optic camera. It can get expensive.

Thank You for the answer, I thought to myself the same thing about the trap in the shower I've search & found OdoBan to combat the odor

Remove the shower drain strainer and poke a stick down there. It should come back with a couple of inches of water behind it. Do you hear any bubbling when you drain or flush? Let me know, Tom