Divya: A 'Script' is just that. I would strongly recommend you search online for words, phrases, sentences, etc, that are structured around offerings, value propositions, etc so you can create your own pitch.
A pitch usually talks about the value you are offering, how it differs from the competitors, your firms core area of expertise [often called Domain expertise] that helps you to get clients to sign up.
On the adherence to the script or pitch, please remember to a) frequently change the words , b) change the pace at which it is delivered, c) change the value proposition - 1 script doesn't suit all and I'll recommend that you keep changing it on every call so it retains the ' freshness ' or you may end up like a tired telecaller!
Hope this helps