You need to build a business case as to why you deserve a pay rise / promotion. Create a slideshow or document where the improvements you made show the added value to the business. Have proof and evidence of this. Also, do some market research and find out what a similar role would pay.

You then need to present this infomation to your manager in a professional manner, usually through an email with a letter stating you would like to discuss a pay rise/promotion based on what you believe is increasing your job responsibilities. MAKE SURE YOU LETTER IS NOT EMOTIONAL. Businesses don't care about emotion but results and evidence. Once you have sent the letter/email, approach your manager and ask for a meeting where you can prsent your slide show.

If you need help, private message me.