you and your negibors will need to pay for putting pegs in.
do you mean the marking stick or the peg stones?
marking pegs
In our contract there was an allowance for missing pegs. At the end of the build as our didn't go missing we we're reimbursed that amount.
Maybe your house contract is the same?
Also, keep in mind that whilst the above ground peg might be missing there is still a good chance the main boundary peg is still there. Ours were 6 inches below the surface.