How do I get refund

I initially attempted buy data from my self earlier today 9th April so I made a mistake in typing my number I typed an invalid number (08149049315) instead of 08149039315 transaction details 1GB₦270.30
Status:Transaction Successful- Apr 09, 11:41 AM
Trans. ID: 202404091141SIJMD40
Your MTN SME 1GB purchase of ₦270.3 on 08149049315 was successful. Old balance: ₦280.17, New balance: ₦9.87