Snapper mower
 

I have a MRP216015B Snapper walk behind. When I cut my lawn, I don't get a
very good cut. I took the mower to the shop where I bought and they
sharpened the blades for me. I got a couple decent cuts and then it is not
so good again. I took it back and they said the blades are still in good
shape. They said that the blades may no be spinning fast enough.

Before I pay for this to be fixed, are there some things I can try at home
to solve the situation?

TIA
Gene