Busted speaker

If you purchased this iPhone within the last 14 days you can return it for either a replacement or a refund. If past then, I suggest that you make a Genius Bar appointment at your local Apple Store or Apple Authorized Service Provider to have them take a look and provide you with your options.

Ref: Genius Bar Reservation and Apple Support Options - Apple

turn your master volume down if it's all the way up. If you're using it all the way up it will sound distorted regardless of musical tastes. if you are using your iPhone for ambient music in the house it would benefit greatly for a pair of powered speakers

I have a similar issue within 3 months of buying the phone, the phone has ben to service station twice and the second time I am given a time frame of a week that too tentative doesn’t a new phone qualify for replacement?

The technician has determined its a repair and the phone has been with the repair centre for 4 days so far and expected for a few more for parts to come and the technician will then check if the phone isn’t repaired if a replacement will be considered. Does staying without a phone for more than a week within 3 months of purchasing a new phone a part of apple’s customer experience? It sure isn’t a pleasant one for me .

Purchase Apple Products from the Apple Online Store, Apple Retail Stores, and many Apple-authorized resellers and wireless service providers.

Only an Apple technician can determine if your iPhone has a manufacturing defect. If they do, then it may be eligible for repair or replacement under the Apple Limited Hardware Warranty.