Who is supposed to fill the pool back up? Is that the company who does it or the owners?
Depends on the project and the contract. Generally the customer pays whatever cost to refill the pool and to monitor the fill process. In the case of a re-plaster the contractor usually ( but not always) adds whatever start-up chems they prefer, and may even require that the customer do nothing but add chlorine to the pool.
20k gal. IG fiberglass/plaster rectangle 32'x16'
Hayward Superpump 3/4 H.P. primary Hayward model 5060 Booster Pump
Hayward Pro Series High Rate Sand Filter
Pentair Model 320 automatic Chlorine/bromine in-line feeder
For plaster pools, the most common arraignment is that the plaster company controls when the fill starts and the home owner is responsible for stopping the fill when the pool is full. Homeowner usually pays for the water, though now and then the builder will pay to have water trucked in and then include that in the overall cost of the project.