You will have to pay a fine of 10 Omani rials ($26) per day if you overstay with an Oman tourist visa.

You can get your queries clarified by making use of the chat feature on Oman IE Visa. Go to Oman IE Visa and you will be able to find the chat feature in the bottom right corner of the website. You can submit your name, email id, WhatsApp and your question to get your doubts clarified. 

Applying for your Oman visa through Oman IE Visa is an online process. Hence, your friend can apply on your behalf. Ensure that you are providing all the correct details and documents.

If you can identify the issue behind the visa rejection, resolve it and then re-apply for the visa.