State Bank Of India [SBI] — the process of sending money to another sbi bank (behala branch)

Address: North 24 Parganas, West Bengal, 743411

Last day i went to sbi basirhat branch to deposit 10k in an account of sbi (Behala). They told me i have to use c. S. P to send money. There was a long line of pensioners. I came back to home. Today i send the 10000 rs. But 80 rs is deducted. Called commission charge.
My question is why i have to use c. S. P, why bank is not provide the service.
Why???