(This continues from where philcrow and runrig left off.)

In

die("Cannot open weekly_${store}_pdf.sas to read from ")
   unless(open(FINAL, ">weekly_${store}_pdf.sas"));
[download]

• the error message is wrong ("read" vs "write"),
• the error message is grammatically incorrect (nothing follows the preposition "from"),
• the error message is incomplete (it doesn't state the reason for the failure),
• the file handle is not localized,
• package variables are used where lexical variables could be used,
• the 2 argument calling syntax of open is used rather than the safer 3 argument calling syntax, and
• the purpose of the statement (open) is hidden deep in the statement.

Fix:

open(my $fh_final, '>', "weekly_${store}_pdf.sas")
   or die("Unable to open weekly_${store}_pdf.sas for writing: $!\n");
[download]

Don't forget to replace the occurences of "FINAL" in the remainder of your code with "$fh_final".