Are they CMU blocks? Is the entire block doing that or just the mortar?
That sounds like an extreme case of deterioration that needs to be addressed ASAP
They will need to be replaced and the water situation mitigated asap.
It's a very fast deterioration, but I don't know what they're sitting in. The CMU manufacturer won't be held for any type of warranty if they're sitting in water. If you had a waterproofing system and this happened, you would have a case, but not with them sitting in groundwater below grade.
No problem. I'm happy to help. If you want someone to replace the blocks, you'll need a good mason and maybe a contractor to shore the wall, depending how much of the block needs to be removed.
You'll also want to have a waterproofing system installed and a drainage course on the outside of the wall.